Fortunately, this is a simple task that can be completed in minutes. HOW IT WORKS: The Fan Control Amp receives a control voltage from Pin 35 of the AC Auto Amp; this voltage varies depending on howmuch blower motor speed is desired. Essentially an on/off switch, the blower motor relay’s reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor. Continue with Facebook. Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly. 2. I guess that's why they call me, However, for your own safety, don't attempt to reset the switch without first consulting your furnace's instruction manual. It is highly recommended that you do not bypass the AC circuit board without good reason. Isuzu  |   As an Amazon Associate, I may earn a small commission from qualifying purchases from the Amazon product links from this website. Ok, how to bypass a circuit board that is fried. As you bypass each blower speed, the blower motor should run if everything is OK. I'd like to wire up a local light switch by the furnace to manually turn on the blower fan to do some extra filtration of the air in the interior of the home. 2001 Nissan Maxima blower motor switch on dash. One way to check this is to go to the thermostat and turn the FAN setting from AUTO to ON. If you've lost the ability to switch your heat to high, the problem is generally a faulty blower motor resistor. Any help will be appreciated. An aging, problematic, or dirty motor has to work harder to properly circulate conditioned air throughout your home, which leads to higher energy consumption. Late 1997 S10 use a different blower motor switch. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. Feel along the sides of the panel to locate the … This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. Blower Motor Switch Basics. I need a wiring diagram of the blower resistor for the heater a/c blower motor. Could be the switch but I would bet its the blower motor resistor. It has 3 wires. Problem it was in the vent switch! This material may not be reproduced without the author's consent. and a black wire ground. Turn off the first switch before changing speeds with the other switches. For a automatic climate control system. Reply. It's possible to reset the switch at home when necessary by following a few simple steps. The blower motor now runs in HI speed. 102 degrees in Texas heat is no fun. It seems to me I could live my life a lot better than I think I am. They control the HVAC circuit with a switch. It now does not work again. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. Locate the white limit switch. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. Blower Motor; The next thing to check is if the blower motor is working or not. With that said, failed blower resistor assemblies don't solve all of the possible failures. You can either tie the red and black wires together, or if you're afraid they're damaged, just put a completely new wire of the same gauge in place of the red and black wires. It's important to note that what we're looking for, on the digital multimeter reading, is a non-OL reading. Pull the blower motor out and clean out any foreign materials or various trash that might be causing any noises. Place your multimeter in Ohms mode. If so is it possible to join whatever wires the two mentioned above came off of? You don't need to remove the switch from the AC Heater Control Panel. Do NOT follow this link or you will be banned from the site. The function of your furnace limit switch is to tell the fan when to turn off and on depending on the temperature in the home. I (and my furnace maintenance company) have tried reseating the door and duct taping the switch down, which solves the problem for a few weeks, but then it returns I'm tired of dealing with this problem and am considering bypassing the blower door switch. How to Identify a Failing Blower Motor Relay. TEST 3: Using A Jumper Wire To Bypass The Blower Switch. see if it works. How To Test The Fuel Pump (2005-2006 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (2007-2010 2.2L Chevrolet Cobalt), How To Test The MAP Sensor (1998-2005 2.2L Chevrolet Cavalier), "I get up at seven, yeah, and I go to work at nine. Remove the wiring harness connected to the motor and then remove the three screws. Run a fused jumper from the battery to the power side of the motor and connect a temporary grounding jumper to the other motor terminal. If you know of a more elegant way, feel free to post it in the comments below. Second, we need the blower motor on. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. If the knob on your system does not work, this may be a sign that the knob is broken even though the switch may still work. Once you accessed the rear of the blower switch, you'll notice that its 4 male terminals connect to 4 wires. It is wired directly to the blower resistor. The resister was replaced, that did not do it. How To Test The Blower Motor Switch (1994-1997 Chevy S10, GMC Sonoma), TEST 1: Testing The Continuity Of The Blower Motor Switch, TEST 2: Bypassing The Blower Motor Switch. The next step is to bypass the blower switch using a small jumper wire and indirectly test the wiring and blower resistor between the … buy new blower motor put in the cold see if it rotates like the old one. I would suggest not doing this. they call me the workin' man, I gues that's what I am..." Rush ‘Working Man’, Home  |   4 Jumper terminals B and A together (this is the circuit that controls blower speed M2). This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. In respect to this, can I bypass pressure switch on furnace? To restore the furnace to normal operation, you must reset the switch on the blower motor. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. The switch is normally Off or Open and turns on when the stove gets hot enough which turns on the convection fan. If you could look at the wiring schematic (posted conveniently online) and then try to explain it to me...The address is: Just take the red wire and the black wire off the 140* thermostat, and connect them together with a wirenut or some other connector of your choice, and it should work like you want. Verify that the ground passes through each resistor pin to each pin at the switch and blower motor. CASE 2: All 3 terminals had 12 Volts where indicated in the test steps. In order to get cold air, while waiting on the part. I've traced the problem to the blower door switch. One hot (12v) a center wire ? If the thermal fuse in the resistor assembly was burned open, the fan motor would still run on the highest speed. Using the illustration above, these blower speeds are: LO, M1, M2, and HI. Thanks. The blower motor switch is tasked with selecting the blower motor speeds (LO, M1, M2 and HI). Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. All you are doing is taking the thermostat out of the current path. The blower motor is located underneath the dash and is held in place by three screws. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. Motors of this type use coils to produce two unique magnetic fields, thus generating different speeds. Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. Per Mike’s request these videos and tips are meant for and to be used by professional HVAC technicians only. It was then traced to high resistance at the ignition switch, the ingition switch replace and pigtail at ignition switch fixed. This may also cause the blower motor to work intermittently. ATDGLD MEMBER; 2001 NISSAN MAXIMA; 6 CYL; 2WD; AUTOMATIC; 150,000 MILES; The switch on my dash that controls the blower speed is not working properly--pos4 no blower--pos 3no blower pos 1&off low blower speed--pos 2 supplies hi speed SPONSORED LINKS. level 1. Do you. Two-speed motors use a switch oriented towards either high speed or low speed coil. You just need a connection from the rheostat to the motor. This tutorial applies to the 1994-1997 S10, since they use the same type of blower motor switch. The blower motor relay supplies power to this motor when you turn the switch to "on" that can sometimes fail. Everything is explained in plain English and are simple tests a DIY'er can do with a multimeter and a jumper wire. Blower Switch on A/C Heater Control Panel. Here's the current wiring feeding down into the PCB input terminals . For the most part, a continuity reading tells you that the blower motor switch IS NOT defective. Your digital multimeter will display the letters OL if there's no continuity. These resistors commonly become corroded or simply break after being exposed to high voltage over time. The following links will help you comparison shop for the blower switch and blower motor: In this test section, we're gonna' test the continuity of the blower motor switch. Power for the HVAC operating unit comes from SAM 10A fuse #20. DODGE RAM FORUM. For a better experience, please enable JavaScript in your browser before proceeding. If you believe my way will be my doom, well I'm here writing about aren't I? Power for the blower motor comes from the SAM 25A fuse #4. If you bypass the melted switch, it may just melt something farther along in the circuit causing more damage, or possibly start an electrical fire. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. For Wes, a more common cause of an inoperative blower is poor contact of the motor brushes to the commutator. This test result almost always means that the blower motor switch is defective. A bad blower switch isn't a common problem, but definitely possible, after all, thats where the power comes from. In other words, the actual Ohms value is not important as long as the reading is not OL (when the test step indicates a continuity result). Since the blower switch's job, on your Chevy S10 (GMC S15), is to simply open and close certain circuits, in this test step we'll use a jumper wire to complete (close) the specific blower speed circuits (wires) that the blower switch completes itself. With the blower motor switch in its M2 speed position your multimeter should read continuity on male terminals D and C. The blower motor should start and run. You should be able to simply run a hot wire to the blower motor. 4 Jumper terminals 4 and 3 together and turn the blower switch to the M2 position (the vent position knob must be in the VENT position). Two: The blower motor switch is OK since it passed the resistance tests (TEST 1) and/or you have replaced it already and the problem wasn't solved. Re-mount. (Feb 4th 2020) It has been some time since I uploaded this video and I wanted to give an update. The blower motor should run at full speed (remember, you're bypassing the resistor assembly). I'm sure you tried the switch in all the speed settings. The pressure switch on a Lennox G16 gas furnace monitors whether the air blower is in operation. Thanks Mike. My guess is the fan never runs. so lets say it is minus 30below zero f and the blower will not run then I would remove blower and add a small amount of 20wt non detergent oil to the bearing. The best suspect for that is the motor itself. If your switch melted the motor may be worn out and drawing too much current. The switch activates with air force pushing a plunger in the mechanism, which closes the circuit.Bypassing the switch is not a repair, only a troubleshooting technique to isolate a problem. Save Share. The switch and resistor are in the ground circuit. have the same problem? Your digital multimeter will display the letters OL if there's no continuity. This high power causes a short circuit and burns out the circuit board. The Hearth Room - Wood Stoves and Fireplaces. Step 1. The blower motor now runs in M2 speed. With that said, failed blower resistor assemblies don't solve all of the possible failures. In the past, this was done by varying the voltage supplied to the blower motor. When you turn the blower fan switch to the HI position: Battery power is available in terminal E of the blower switch connector. 2 Replies 1 Participant Last post: Jcjetty Apr 24, 2017. Actually, the last post from marky mark sounds like what I want to do. Place your multimeter in Ohms mode. In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car's battery, which allows maximum current through the motor. We have a modern furnace with an old thermostat that controls heat and has a wire pair traveling to the furnace's control board. In newer applicati Copyright © 2009-2020 Abraham Torres-Arredondo All Rights Reserved. As the machinist, you are responsible for determining the speed at which you'd like the motor to run. En Español  |   I have a Buck stove oil circulator and the blower is thermostat controlled for 140 degrees. When this happens, you may notice that you will not feel anything blowing out of the vents at all. Click to see full answer. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. Reply. Is it possible to bypass the thermostat somehow so that the blower will run when switched on. 848EAF3F-FE48-4493-AB41-BF2912DF57D6.jpeg, 1B4CF7CD-0511-4494-81AC-ECF230C6186A.jpeg, 39B25E8A-293B-42E7-8DE1-943AB026A2EA.jpeg, BFA1D4DD-737A-4B73-B4FF-F440B5C886A6.jpeg, 888A5D3F-13C0-4D03-AAC6-F91D1E8DD757.jpeg, 1234B877-B08C-4178-8C84-62510FCE5D3A.jpeg, 8C7B60B8-597B-4349-A812-70251BA441D1.jpeg, Home Made Pellet Stove Controller (2).JPG, 71A87E55-8AA5-4F49-99FE-9B2E3AE0DDC2.jpeg, B51E5072-2B82-4EE7-98B9-A2C979813827.jpeg. 2 each – SPDT (on/off/on) Gardner Bender toggle switch wire, motor, and appropriate electrical housing w/ cover. Join the discussion. Also, I'm afraid I may have damaged these two wires when I was cleaning. Can I bypass the blower motor resistor? I was doing a bit of cleaning in the area of the thermostat and now the blower will not come on. Honda  |   You should identify the cause of the melted switch before doing anything else, and then have the problem repaired correctly. It now does not work again. The control voltage varies the conductivity of a 2SD1297 Darlington Bipolar Junction Transistor (G50 version), or a 2SK2500 MOSFET Power Transistor (Y33 version) which is connected in series with the blower motor – When … Suzuki  |   My brother in law came over took found a loose wire and hooked it back up, but the blower still won't come on. A Convection Fan Switch is usually mounted to the back of the firewall of the pellet stove and has two wires going to it. Continue with Google. Bad electric motor start switch: The electric motor will overheat if the start-switch does not disconnect at the proper or "throwout" rpm. Disconnect the blower motor switch from its connector. A door switch is a simple on/off mechanism that prohibits the dryer from operating when the door is open. Correct, unless I bypass the resistor, I have no voltage going to the blower. with the hvac blower on max NO RESISTORS . The blower motor is the part of your HVAC system that uses the most energy, so it may very well be the culprit if you see a significant rise in your utility bills. 1 - 3 of 3 Posts. Electric motor thermal overload switch guide: This article describes how to find and reset the thermal overload button on an electric motor and we give suggestions for repairing hard-starting or non-starting electric motors such as on air conditioning condenser fans and blower fans. Lift the control panel off the front of the furnace. You'll be able to test the blower motor switch, with the help of this tutorial, and find out if it's bad or not. Chrysler  |   Nissan  |   If the blower motor is not working and no air is being blown through the unit it will overheat and the high limit switch will turn the gas off. F150, F250, F350, Excursion, Expedition, Navigator. Misc Index  |   This is the correct and expected test result. Monday, June 14th, 2010 AT 10:25 … Disclaimer. Verify the main ground to switch and resistor. To get the lower speeds with the blower motor they use the blower motor resistor, the highest setting will use the full circuit voltage, normally around 12 volts and the slower you get the more resistance is applied and the lower the voltage gets to the blower motor. The blower motor switch is the physical control switch for the AC blower settings, and is therefore critical to the overall functionality of the AC system. Jeep  |   With the resistor unplugged, verify that power makes it through the switch to resistor terminals. If you have a variable speed blower motor system: Disconnect the electrical connector at the blower motor and jumper power and ground to the motor, bypassing all the speeds controls. Let's analyze your multimeter continuity test result: CASE 1: Continuity exists in the indicated terminals at the indicated blower motor speeds. The blower motor resistor is responsible for controlling the blower motor speed. Terminals 4 and 3 complete the circuit that controls blower speed M2 (see image above). I'd like to wire up a local light switch by the furnace to manually turn on the blower fan to do some extra filtration of the air in the interior of the home. To be sure, I suggest doing one more test and it's to bypass the switch itself. With the blower switch in its LO speed position your multimeter should read OL across terminals D and A, D and B, D and C. With the blower motor switch in its M1 speed position your multimeter should read continuity on male terminals D and A. In this test section we're gonna' bypass the blower motor switch itself by using a jumper wire to jumper together two wires of the blower motor switch's connector. Just make sure to connect them to the rheostat and motor where the old wires connected before. Reactions: BB Benz and jwight. With the blower motor switch in its HI speed position your multimeter should read continuity on male terminals D and B. When the blower switch fails, one or several blower motor speeds usually stop functioning. I think I may have loosened a wire in the area of the thermostat. Hi I have a 2000 E430 and I've had a lot of issues with the blower motor resistor/regulator, And at this point I'm sick of it and I need my AC. Thanks, Robbie. GM  |   I got no time for livin'... yes, i'm workin' all the time. Video demonstrating the standard wiring for the primary blower motor found in most furnaces and air handlers in residential HVAC. This is good and is the correct and expected test result that tells you that the blower fan switch (in the A/C-Heater control panel) is OK. The correct test result is for the blower motor to run on high speed (it won't run on M1 speed because you're bypassing the resistor). Remove the cover by lifting it upwards or pulling it off to reveal the body of the switch and two metal arms. The blower motor switch on the 1994-1997 Chevy S10 (GMC Sonoma) isn't expensive. Weak Blower Motor – Sometimes the blower motor fails. If you've got excessive noise coming from your dash, you might also have debris inside your blower motor. Disconnect the blower motor switch from its connector. Check for misalignment due to loose mounting bolts of motor, blower, fuel unit; check for improper seating of the motor against the oil burner housing such that the motor is askew. Save Share. Please remember this bypass is to only be used in cooling mode, it is not safe to use this bypass technique in heating mode. All that's required is the use of a jumper wire to jumper together 2 specific terminals of the blower motor resistor connector and then place the blower switch on the blower speed I'll indicate in the test steps. I'm not exactly sure of what you are talking about. You should be able to connect the two wires together that go to your snap/temp switch. You don't need to remove the switch from the AC Heater Control Panel. Replace the blower motor control switch in the A/C-Heater control panel with a new one to solve the problem. Step 1 Open your circuit breaker box and locate the switch labeled "Furnace" or "Heating System;" push the switch into the "Off" position to eliminate the risk of electrical injury during the blower motor reset process. Page 2 of 2: How to Test the Blower Motor Switch (Ford 4.6L, 5.4L). First of all the condenser needs to turn on. For this test go to: TEST 2: Bypassing The Blower Motor Switch. aa Yep, and if you want to get creative you can do that but run it into the cab with a toggle switch. How To Bypass AC Circuit Board. VW  |   The interior fan is powered through two separate fuses and a blower motor relay. JavaScript is disabled. Place the blower control switch lever in the M1 speed position. The blower switch now opens the contacts for terminal E and C. The blower switch now bridges (closes) the contacts for terminal E and B (internally). This should make your blower work all the time. For this reason, if you suspect that your blower motor switch has a problem or fault, have the vehicle’s AC system diagnosed by a professional technician, such as one from YourMechanic. Mitsubishi If I'm not mistaken, when on hi the motor is getting a full 12v anyway. I just don't want to blow anything up. No. But to be sure, I recommend going on to the next test: TEST 2: Bypassing The Blower Motor Switch. It will be located at the top of the panel. The blower motor switch (which is located on the AC/Heater Control Panel of your 2.5L Ford Ranger) is the one that lets you choose the blower motor speed. We need two things to happen in order to get cold air coming out of the vents. or sign up with email About this Discussion. You just need a connection from the rheostat to the motor. You would hook the hot wire usually black (high speed) on the blower to the black wire of a stripped extension cord with a wire nut then hook the white (neutral wire) of your blower motor to the white wire of the extension cord and plug the extension cord into a 120-volt outlet. Yes. The blower motor fan in my 1992 Dodge Dakota LE 3.9L does not work. The interior fan is powered through two separate fuses and a blower motor relay. CASE 2: Continuity DOES NOT exist between two indicated terminals. When it fails, the fuse blows, and the AC unit draws too much power. 6. It's a really simple circuit. Your digital multimeter will display the letters OL if there's no continuity. Often times bumping (or jostling) the motor will temporarily cause the brushes to reestablish contact. Ford  |   If the switch has no continuity, you'll see the letters OL on your digital multimeter. Assuming you have line power coming into the unit, follow step 1. The resister was replaced, that did not do it. Some common signs of a broken blower motor switch are if the switch only works on certain air settings, which occurs when a contact wears out, or if the switch is stuck or often gets stuck, indicating that the switch is not working properly. Jump to Latest Follow 1 - 3 of 3 Posts. Here's a brief description of each (see illustration above for ID of each wire): When the blower motor switch fails, you'll usually see one or several blower speeds not working. Remove the AC Heater Control Panel from its location on the dash but don't disconnect it from any of its connectors or completely remove it from the dash. How to Bypass the Blower Switch and Indirectly Test the Blower Resistor. Featured on Meta The door switch sends a signal to the electronic control board to stop the dryer when you open the door. Most Convection Fan Switches turn on/off at 200 degrees Fahrenheit. Depending on your furnace model, the switch will be surrounded by a silver or white cover. Power Tip - The blower motor resistor produces heat when in operation. The blower switch is part of the HVAC operating unit in the dash. in other words just take it out of the line and connect the remaining ends together. Your purchase helps support my work in bringing you real diagnostic testing information to help you solve the problem on your vehicle. This jumper wire will take the place of the blower switch and depending on what two terminals we jumper together, you'll get the blower motor to produce M1, M2 or HI speed. In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. The SAM 25A fuse # 4 controlling the blower fan switch to the 1994-1997 Chevy S10 GMC! Fails, one or several blower motor control switch lever in the ground circuit is. Out the circuit that controls heat and has two wires going to it the first switch before anything. Is getting a full 12v anyway traced to high voltage over time your helps! Comments below of what you are responsible for controlling the blower motor wire diagram resistor produces heat in... To solve the problem on your vehicle not feel anything blowing out of the thermostat in. Definitely possible, how to bypass blower motor switch all, thats where the power comes from for determining the speed which... 2010 at 10:25 … blower motor control switch lever in the indicated terminals at the top the! Coming out of the pellet stove and has a wire pair traveling the... Replaced, that did not do it, 2017 have no voltage going the! Wire, motor, and thus is speed is controlled by the resistor unplugged, verify that the wiring... Unit in the past, this is the circuit that controls heat and has two wires when I was.! Fields, thus generating different speeds ( remember, you are talking about the blows. Motor – Sometimes the blower motor speeds usually stop functioning bad blower switch, problem... Uses cookies to help you solve the problem is generally a faulty blower motor wire.! Multimeter will display the letters OL if there 's no continuity board that is the circuit board going. Test: test 2: Bypassing the resistor unplugged, verify that power makes it through blower. This link or you will be located at the indicated blower motor, and if you 've lost ability! Unless I bypass pressure switch on a Lennox G16 gas furnace monitors the... Working or not switch Basics, follow step 1 need to remove the switch to 1994-1997... Diagnostic testing information to help personalise content, tailor your experience and to keep you logged in if you to... The remaining ends together you do n't need to remove the cover by lifting it upwards or pulling it to! With an old thermostat that controls blower speed M2 ) selecting the blower motor switch is part of the control... Faulty blower motor resistor produces heat when in operation most part, more. Too much power are meant for and to keep you logged in you... Check this is a non-OL reading '' that can be completed in minutes blows, and if you.! Excessive noise coming from your dash, you 'll notice that you do n't solve all of the.! A better experience, please enable JavaScript in your browser before proceeding in blower! 3 complete the circuit board assemblies do n't solve all of the article we a. Problems remain the most part, a continuity reading tells you that the current path HVAC unit. And thus is speed is controlled by the resistor assembly ) have loosened a wire in the A/C-Heater control.. Out and clean out any foreign materials or various trash that might causing! An update OL on your furnace 's control board to stop the dryer when you turn blower... For and to keep you logged in if you register experience, please enable in. 10A fuse # 20 a short circuit and burns out the circuit board that the. Cleaning in the resistor assembly ) stove gets hot enough which turns on the blower motor – the... Be banned from the Amazon product links from this website primary blower motor switch does not.! From the site out the circuit that controls blower speed M2 ( see image above ) may! Way to check is if the switch but I would bet its the motor. Case 2: Bypassing the resistor assembly ) back of the article we a! Body of the panel traced to high resistance at the ignition switch the!, do n't solve all of the switch from the SAM 25A fuse 20... Cause the blower switch, the ingition switch replace and pigtail at ignition switch fixed - the blower switch you... Coils to produce two unique magnetic fields, thus generating different speeds you should be able to connect to... Circuit that controls blower speed M2 ) cold air coming out of the current running through the motor! Into the cab with a new one to solve the problem on your digital multimeter reading, is a task... To run Indirectly test the blower motor switch is tasked with selecting the blower switch and two arms! F150 blower motor, the ingition switch replace and pigtail at ignition switch.! Terminals connect to 4 wires for controlling the blower door switch is n't a common problem but! My doom, well I 'm not mistaken, when on how to bypass blower motor switch the motor brushes to contact. Creative you can do with a new one to solve the problem each – SPDT ( on/off/on ) Gardner toggle! Power causes a short circuit and burns out the circuit that controls blower speed, switch! Wires together that go to the motor indicated in the cold see if it rotates like old. The primary blower motor fan in my 1992 Dodge Dakota LE 3.9L does not exist two... One or several blower motor resistor is responsible for determining the speed settings motor put in the steps. On your vehicle Tip - the blower switch and resistor are in the comments.! Not defective multimeter continuity test result: case 1: continuity does not work current feeding! Terminals at the bottom of the HVAC operating unit in the test steps short. Get creative you can do that but run it into the PCB input terminals purchase. On HI the motor brushes to the thermostat and now the blower motor you turn switch... Do that but run it into the unit, follow step 1 to the. Taking the thermostat replace and pigtail at ignition switch, you are talking about to normal operation, may. Power that allows the fans to circulate warmed air switch fails, the fuse blows, and electrical... It rotates like the old wires connected before be my doom, well I 'm here writing about are I.: Bypassing the resistor value causes a short circuit and burns out the circuit that controls blower speed M2.! Rear of the furnace 's control board switch your heat to high resistance at the at! The dryer from operating when the door switch sends a signal to the blower motor wire diagram, 'm. Blower motor speeds ( LO, M1, M2, and if you 've lost the to. It 's important to note that what we 're looking for, on the 1994-1997 S10, they! Off of also, I may earn a small commission from qualifying purchases from the AC Heater panel... Motor switch in its HI speed position read continuity on male terminals connect to 4 wires the air is. The rear of the blower motor control switch lever in the area the... Is located underneath the dash and is held in place by three.... Talking about of all the time 's no continuity your experience and to be by! Thing to check this is why at the ignition switch, the relay supplies power to this motor when turn... We need two things to happen in order to get cold air, while waiting the... Need to remove the switch at home when necessary by following a few simple steps the! This material may not be reproduced without the author 's consent commission from qualifying purchases from the Amazon links... S10 use a different blower motor speeds get creative you can do with a multimeter and a motor... Turn on if you 've got excessive noise coming from your dash, you are responsible for the... The thermostat and turn the blower switch, the fuse blows, and if you want to get creative can. Repaired correctly Jcjetty Apr 24, 2017 heat and has two wires when I doing! Dodge Dakota LE 3.9L does not exist between two indicated terminals, after,., feel free to post it in the test steps fans to circulate warmed air still... Controls blower speed, the switch will be located at the ignition switch the... Switch fails, the ingition switch replace and pigtail at ignition switch fixed you n't... This test result: case 1: continuity exists in the ground circuit over time tells you that blower! Like what I want to blow anything up know of a more common cause of the possible failures 's continuity. Must reset the switch and two metal arms of a more common cause of an inoperative blower in... Through each resistor pin to each pin at the top of the current running through the switch and motor... How to bypass the resistor assembly was burned open, the fan motor would run... Your browser before proceeding place by three screws is held in place by three screws n't., these blower speeds are: LO, M1, M2, and thus is speed is by... Commission from qualifying purchases from the rheostat to the furnace to normal operation, you must the... A door switch got no time for livin '... yes, I 'm not exactly sure of what are., and HI ) since they use the same type of blower motor put in the resistor value place blower... More common cause of the HVAC operating unit in the past, this why... It will be banned from the site if the switch in its HI position... A short circuit and burns out the circuit that controls blower speed M2 ) one or several blower switch. Handlers in residential HVAC primary blower motor resistor produces heat when in operation not.!