8.9K subscribers Subscribe 1.6K views 2 years ago how to diagnose fan motor from wiring diagram with blower resistor Network this explains all of the speeds of the fan motor and how the...Changed blower resistor, pigtail and blower motor and it's still not working. Did the same 14 months ago and it corrected the problem. Not sure if the wires aren't connected correctly or if there coul …Followed these instructions and found a break in the connection between wire and connector in one of the wires of the adaptor. How this came to be, is a mystery but I managed to open the little female metal pin connector at the end of the wire, reattach it with fiddling and some tape en reassembled the thing. Works perfect for now. Blower motor wiring diagrams for three or four speed systems. Carmakers use these three common wiring methods to supply power and ground to the blower motor in a manual system using a blower motor resistor.Version. Listed below is the vehicle specific wiring diagram for your car alarm, remote starter or keyless entry installation into your 1998-2001 Dodge Ram . This information outlines the wires location, color and polarity to help you identify the proper connection spots in the vehicle. Please be sure to test all of your wires with a digital ... First off check for voltage at the connector to the motor with switch in all positions getting anything. Check for damage of the wires in the connector. These cars had a issue with them not being tight and causing high resistance and melting them up. Also, some have found that the connector on the back of the switch for selecting the fan to ...A wiring diagram is a simple visual representation of the physical connections and physical layout of an electrical system or circuit. It shows how the electrical wires are interconnected and can also show where fixtures and components may be connected to the system. Back to top.Aug 3, 2023 · The blower motor resistor controls the fan speed of your vehicle’s blower motor. A faulty blower motor resistor hampers the operation of the heating and air conditioning system. If your air-conditioning fan only works at some speeds but not at others, then the resistor might be suspect. The black wire pin should be ground, one should be 12 volts coming in , the other 3, low fan, mid fan, and high which should bypass resistor completely. One of the other guys can maybe help beyond that with testing, but besides the ground, I'd test on ohm scale of your meter and see what you get between old resistor, and new.First off check for voltage at the connector to the motor with switch in all positions getting anything. Check for damage of the wires in the connector. These cars had a issue with them not being tight and causing high resistance and melting them up. Also, some have found that the connector on the back of the switch for selecting the fan to ...Mar 20, 2018 · S. srraviindran Discussion starter · Mar 20, 2018 (Edited) E90, 320d 2012, The a/c blower unit circuit is not receiving signal, checked panel switch, blower resistor, and just wont get voltage. Rechecked ac heater, blower module, no supply reaching. Jan 14, 2009 · 7. 72ElCamino · #3 · Jan 15, 2009. Re: 71 blower motor resistor wiring. grumpyschevelle said: I was able to find a previos thread that mentioned the relay wiring and what wire went to what terminal blade. Im still at a loss on the wiring that goes to the blower motor resistor though. Aug 5, 2019 · The problem is in the wiring harness or the resistor for the blower motor. Its not the usual 1 3 that doesnt work none of the chevrolet 2004 colorado question. Wiring diagram for blower motor in 2004 chevy impala motor wire. Wiring diagrams before you call a ac repair man visit my blog for. Aug 20, 2020 · Blower Wiring Diagram for 2010 F150. I need a blower wiring diagram &/or advise for a 2010 F150, 5.4L, 2009-2014 should be the same. Can't find diagram here or on Google. Most of the time my blower does not work but it comes on about once a week, in high I think but not very strong. I replaced the fan resistor but that didn't help. This is a great write-up by the way, thanks very much for doing this. A couple of things that I would add: If you are like me and like to test things out before putting it all back together, you need to realize that the giant green resistor gets very hot when it is being used, in fact it depends on the same air that it controls and is blowing by it to cool off.sounds like the drivers temp door actuator is not working should be located on the drivers side of the air box down by the gas pedal or center dash area. Electrical Problem 1994 Buick Lesabre. GM usually puts the Fuse Diagram in the Back of the Owners Manual. cruise control won't work, 10 amp. fuse in fuse box under hood ok.Feb 21, 2021 · Good evening and thank you for requesting me! The blower motor resistor will be mounted right next to the blower motor. It will have a 4 or 5 pin plug and it's mounted in the hvac case right next to the blower so that it always has air flow to keep it cool. I'll see if I can send you a parts diagram. Are any of the controls working? # 1 low speed .Looking at a wiring diagram I would think that impossible . # 1 position for low speed would need to go through all the resistors in the resistor pack , which would mean all others good . # 5 high speed doesn't use resistors . uses a relay an direct B+ to the blower motor .Feb 4, 2022 · The most common causes for AC fan blower motor not working in Ford Fiesta are blown fuse, bad relay, resistor or control module malfunction and faulty blower motor. However, a bad electrical connector or broken wire, or a defect in the climate control unit can also cause the blower motor to stop working. 1. 3Ø WIRING DIAGRAMS 1Ø WIRING DIAGRAMS Diagram ER9 M 3~ 1 5 9 3 7 11 Low Speed High Speed U1 V1 W1 W2 U2 V2 TK TK Thermal Overloads TWO SPEED STAR/DELTA MOTOR Switch M 3~ 0-10V 20V 415V AC 4-20mA Outp uts Diagram IC2 M 1~ 240V AC 0-10V Outp ut Diagram IC3 M 1~ 0-10V 4-20mA 240V AC Outp uts These diagrams are current at the time of publication ...Jul 13, 2023 · Slide it toward the rear of the vehicle to remove it. Figure 3 The green arrow points to the blower motor resistor and the red arrow points to the blower motor. All testing will be performed at the resistor. Figure 4 Start by connecting your DVOM to the power feed. Connect your red lead to terminal 4. Blower Motor Resistor Wiring Diagrams. A blower motor resistor works by routing power through 1, 2, or 3 in-series resistors. See the blower motor resistor wiring diagrams below to see how it works on each speed. Posted on June 26, 2020 by Rick Muscoplat. eautorepair.net.Blown heater motor resister, melted speed switch, melted wires in steering column. The Fix: Adding relays in the heater circuit. You will also need to replace your blower motor resistor, and selector switch if you have not already done so. Parts Needed: 4 relays. 10 feet red 12 gauge wire.mentions fuses keep popping, i removed the dash panels to access the blower motor etc, pulled wiring harness out and load tested all wiring coming from blower motor to HVAC controller, all good. have good 12V supply (Pin1) and good Ground (Pin3), at the blower motor connector. pins 4 and 6 only have a max ofVersion. Listed below is the vehicle specific wiring diagram for your car alarm, remote starter or keyless entry installation into your 1998-2001 Dodge Ram . This information outlines the wires location, color and polarity to help you identify the proper connection spots in the vehicle. Please be sure to test all of your wires with a digital ...miami5th said: If you buy the Mopar kit with the upgraded resistor you have to swap the wire orientation coming from the resistor to the blower motor. I believe it's a green and black wire set. I just focused on the plug that goes into the blower motor. No need to slice and splice to change the wire orientation.made sure the blower fan could spin and made sure no obstructions 2a. cleaned the cabin filters 3. can power up the blower directly with a different power source and it works 4. blower relay checked out okay 5. blower resistor checked out okay 6. downloaded a manual to look at wiring diagrams - where i'm currently at, to see what I could also ...Sep 17, 2014 · Wiring diagram for 1999 nissan maxima blower switch. Replaced blower motor resistor but fan for heat and ac works on high only. suspect switch is bad. would like wiring diagram for blower motor switch to test switch to verify its bad. Posted by Anonymous on Sep 17, 2014. The wiring diagram of the blower motor resistor is shown below. The following diagram shows how the resistor is connected to a car. The resistor has the highest fan speed setting that will be bypassed within this car & the blower motor can be power-driven through the switch of a fan.This is a great write-up by the way, thanks very much for doing this. A couple of things that I would add: If you are like me and like to test things out before putting it all back together, you need to realize that the giant green resistor gets very hot when it is being used, in fact it depends on the same air that it controls and is blowing by it to cool off.In most cases it's the blower motor resistor. Below is a diagram of its location, the plug and how to remove it. Looking at the picture of the plug you will want to turn the fan switch to different settings (the ones that don't work as well) and if you are geting power to each of those conections at the plug but the blower motor isn't turning on, this will be your problem.so i have replaced the resistor and wiring harness and ac worked great for 3 days, now nothing. i replaced the blower motor and still nothing. i am showing 12-15v at each fan setting, 0v through the ground, and 12-15v from the resistor to the blower motor through the black wire. all fuses are appear to be ok and i am at a loss.Aug 3, 2023 · The blower motor resistor controls the fan speed of your vehicle’s blower motor. A faulty blower motor resistor hampers the operation of the heating and air conditioning system. If your air-conditioning fan only works at some speeds but not at others, then the resistor might be suspect. The average replacement cost of a blower motor resistor is between $90 and $175. Expect to spend about $40 to $100 on the part and another $50 to $75 for labor if you can’t perform the replacement yourself. However, you should bear in mind that the most common reason for a bad blower motor resistor is due to a bad fan motor.Engine: 350 cam, boltons/350/cam boltons. Transmission: 700r4/700r4/M6. Axle/Gears: 3.73/3.43/3.43. Heater Blower Motor, Resistor, Relay, and more... Heater Blower Motor Information. So, after searching a million threads and asking a million questions I finally got the information I needed. But it took a very long and rather boring time to do ...mentions fuses keep popping, i removed the dash panels to access the blower motor etc, pulled wiring harness out and load tested all wiring coming from blower motor to HVAC controller, all good. have good 12V supply (Pin1) and good Ground (Pin3), at the blower motor connector. pins 4 and 6 only have a max of Mar 20, 2018 · S. srraviindran Discussion starter · Mar 20, 2018 (Edited) E90, 320d 2012, The a/c blower unit circuit is not receiving signal, checked panel switch, blower resistor, and just wont get voltage. Rechecked ac heater, blower module, no supply reaching. The black wire pin should be ground, one should be 12 volts coming in , the other 3, low fan, mid fan, and high which should bypass resistor completely. One of the other guys can maybe help beyond that with testing, but besides the ground, I'd test on ohm scale of your meter and see what you get between old resistor, and new.Mar 20, 2018 · S. srraviindran Discussion starter · Mar 20, 2018 (Edited) E90, 320d 2012, The a/c blower unit circuit is not receiving signal, checked panel switch, blower resistor, and just wont get voltage. Rechecked ac heater, blower module, no supply reaching. Nov 2, 2015 · On a 66 heater (no ac car) the blower fan power is fed via the orange wire from the heater motor. That wire goes back through the bulkhead connector, so check and clean that connection. From there it goes to the heater blower resistor, inside the car, on top of the heater box under the glove box. On most american and import cars and light trucks, the blower resistor is located near or on the blower motor. Check out this guide to oven wiring problems, and to finding those oven wiring diagrams that you need. A blower motor resister in a vehicles works in conjunction with the heater control panel fan switch to control the speeds of the fan.Just replaced blower motor resistor to fix fan not coming on. How to test the blower motor resistor 2001 2004 dakota durango. You ll notice that the blower motor is a simple 2 wire component. Dodge was founded in 1914. Variety of 2002 dodge dakota wiring diagram. Cómo probar el motor del soplador 2001 2003 dodge dakota and durango at.sounds like the drivers temp door actuator is not working should be located on the drivers side of the air box down by the gas pedal or center dash area. Electrical Problem 1994 Buick Lesabre. GM usually puts the Fuse Diagram in the Back of the Owners Manual. cruise control won't work, 10 amp. fuse in fuse box under hood ok.Aug 3, 2023 · The blower motor resistor controls the fan speed of your vehicle’s blower motor. A faulty blower motor resistor hampers the operation of the heating and air conditioning system. If your air-conditioning fan only works at some speeds but not at others, then the resistor might be suspect. S. srraviindran Discussion starter · Mar 20, 2018 (Edited) E90, 320d 2012, The a/c blower unit circuit is not receiving signal, checked panel switch, blower resistor, and just wont get voltage. Rechecked ac heater, blower module, no supply reaching.Heater blower motor randomly stopped working. Put 12v to the fan and it spins. Bought a replacement fan with a new resistor module Tried different climate control module Checked all wiring from fan to climate control module to fuse box. All is good and getting 12v. Checked fuses and relays 2007 GTIBuy Now!New Blower Motor Resistor from 1AAuto.com http://1aau.to/ib/1AHBR00086The heat and air condition fan is controlled by a separate module, called the b...Dec 8, 2014 · On my 1066, though, the blower has a similar wiring setup. The three wires from the motor are indeed the speeds. If you put 12v of power to each one in turn, the motor should run at whatever speed you have powered. One terminal on the switch should have battery power. The other may be for powering an air conditioner unit. Oct 1, 2020 · Just replaced blower motor resistor to fix fan not coming on. How to test the blower motor resistor 2001 2004 dakota durango. You ll notice that the blower motor is a simple 2 wire component. Dodge was founded in 1914. Variety of 2002 dodge dakota wiring diagram. Cómo probar el motor del soplador 2001 2003 dodge dakota and durango at. Aug 22, 2023 · The average replacement cost of a blower motor resistor is between $90 and $175. Expect to spend about $40 to $100 on the part and another $50 to $75 for labor if you can’t perform the replacement yourself. However, you should bear in mind that the most common reason for a bad blower motor resistor is due to a bad fan motor. Jan 16, 2013 · 4. Remove the 2 screws that secure the blower motor resistor or controller to the heater-AC housing. 5. Remove the blower motor resistor or controller from the heater AC housing. INSTALLATION 1. Install the blower motor resistor or controller to the heater AC housing. The housing is indexed to allow (controller power module) mounting in only one Aug 20, 2020 · Blower Wiring Diagram for 2010 F150. I need a blower wiring diagram &/or advise for a 2010 F150, 5.4L, 2009-2014 should be the same. Can't find diagram here or on Google. Most of the time my blower does not work but it comes on about once a week, in high I think but not very strong. I replaced the fan resistor but that didn't help. Jun 26, 2020 · Blower Motor Resistor Wiring Diagrams. A blower motor resistor works by routing power through 1, 2, or 3 in-series resistors. See the blower motor resistor wiring diagrams below to see how it works on each speed. Posted on June 26, 2020 by Rick Muscoplat. eautorepair.net. Figure 1 If your blower or fan motor runs at full speed regardless of the setting you have it on there is a very good chance your resistor is bad. The resistor is located below the blower motor in the cabin air box (red arrow). Please see our article on blower motor replacement for additional assistance on removing the motor.Administrator. Joined: Nov 2003. Posts: 6,035. Illinois. I found discrepancies in wire colors between the '68 AC wiring diagram and the schematic on the '68 Diagnosis Manual too. For example, the wiring diagram shows a black-orange stripe to the blower motor yet my '68's wiring agrees with the Diagnosis schematic purple wire to the motor.If the same as on a 93 the wiper motor has two connectors. Connector A (motor): wiper switch to motor (high) - dark brown / orange. wiper switch to motor (low) - white. ground - black. Connector B (park switch): wiper switch to motor (park and return) - red. wiper switch to motor (park return) - black. ground - black.Dec 27, 2014 · # 1 low speed .Looking at a wiring diagram I would think that impossible . # 1 position for low speed would need to go through all the resistors in the resistor pack , which would mean all others good . # 5 high speed doesn't use resistors . uses a relay an direct B+ to the blower motor . Understanding the Wiring Diagram for a Blower Motor Resistor. To properly understand a wiring diagram for a blower motor resistor, it is important to understand how the components work together. The diagram will show the connection between the board, resistor, switches, and thermal fuse.Jan 8, 2016 · A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system. Usually a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue. 1. Blower motor stuck on one speed. A common symptom of a faulty blower motor resistor is a blower motor ... helpful. answers. The blower motor brushes may be worn down, when that happens, a bump or vibration may cause the blower motor to start running again. If that is the problem, the fix is a new blower motor. When problem is ongoing, check blower motor wiring connector for voltage and ground, if both are good and no blower action, what else could ...Jun 19, 2022 · BASIC BLOWER RESISTOR WIRING DIAGRAM (POSITIVE SWITCH CONTROL)Panibagong video na naman ang aking nais ibahagi sa inyo mga bossing. So sa video na ito itutur... Aug 22, 2023 · The average replacement cost of a blower motor resistor is between $90 and $175. Expect to spend about $40 to $100 on the part and another $50 to $75 for labor if you can’t perform the replacement yourself. However, you should bear in mind that the most common reason for a bad blower motor resistor is due to a bad fan motor. Aug 28, 2020 · looking at diagram 68/69 diagram ( 70 maybe the same ? ), High speed is a straight feed from the switch not going through the resistor block, just like 71/74 are. Its spliced into the resistor block just to use that wire to source the output from resistor block to the blower with the speed selected using just one wire for the blower. Hi I have a 2012 Ford Fusion 4 cyl with atc. The blower motor resistor connector was some what burnt. I replaced the blower motor, resistor, & resistor wire connector. The issue was that a/c would int … read moreJul 15, 2017 · Hi I have a 2012 Ford Fusion 4 cyl with atc. The blower motor resistor connector was some what burnt. I replaced the blower motor, resistor, & resistor wire connector. The issue was that a/c would int … read more Jun 19, 2008 · No, the resistor will easily come off and rep-connect. Just trace the red/back from the resistor and you'll find it plugs into the fan motor. That is the easiest part of this repair, the splicing of wires is the hardest. As smith mentioned, pay attention to the wire order so you don't do what I did first. The blower motor consists of the blower fan and motor. A sirocco fan has been adopted for the blower fan. Operation. 1. The front body control module (FBCM) turns on the blower relay based on the blower ON signal sent from the climate control unit. 2. When the blower relay turns on, the blower motor fan rotates. 3. The rotation speed of the ...Mar 20, 2018 · S. srraviindran Discussion starter · Mar 20, 2018 (Edited) E90, 320d 2012, The a/c blower unit circuit is not receiving signal, checked panel switch, blower resistor, and just wont get voltage. Rechecked ac heater, blower module, no supply reaching. Import Direct Ignition 4 Terminal Blower Motor Resistor - 30-0117. Your vehicle's blower motor resistor controls the speed of your blower motor. When you turn a knob to produce more air flow for heat or cool air, the resistor adjusts the electrical resistance to control the power sent to your blower motor. Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. With that said, failed blower resistor assemblies don't solve all of the possible failures. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram. The interior fan is powered through two ...Jun 1, 2013 · In most cases it's the blower motor resistor. Below is a diagram of its location, the plug and how to remove it. Looking at the picture of the plug you will want to turn the fan switch to different settings (the ones that don't work as well) and if you are geting power to each of those conections at the plug but the blower motor isn't turning on, this will be your problem. Hooked the brown wire to the positive battery terminal, the yellow to the negative, I heard the fan spin- so, the fan blower is operational. Step 2. If that works reconnect them. Turn the ignition on. Take the wire, should be yellow, off of the resister on the heater box and ground it. The fan should also spin.Import Direct Ignition 4 Terminal Blower Motor Resistor - 30-0117. Your vehicle's blower motor resistor controls the speed of your blower motor. When you turn a knob to produce more air flow for heat or cool air, the resistor adjusts the electrical resistance to control the power sent to your blower motor.The heater blower motor stops working ? Testing the electrical circuit would be the proper way to diagnose . Looking at a wiring diagram an using a DMM - digital multi-meter , an doing amp draw test on the blower motor . The PRND321 an blower motor probably share a ground or power point . Looking at a wiring diagram for both circuit's would ...Hooked the brown wire to the positive battery terminal, the yellow to the negative, I heard the fan spin- so, the fan blower is operational. Step 2. If that works reconnect them. Turn the ignition on. Take the wire, should be yellow, off of the resister on the heater box and ground it. The fan should also spin.Sep 27, 2012 · 2005 T'Blazer, 6 cylinder, manual A/C controls. Maybe 6 months ago, blower fan speed 5 stopped working, followed by the rest shortly after. Following the great advice on this forum, I checked the blower motor resistor and plug, and replaced as advised. Sure enough, everything worked fine once again. A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system. Usually a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue. 1. Blower motor stuck on one speed. A common symptom of a faulty blower motor resistor is a blower motor ...
A small module was replaced--- I believe it was know on the forums as the blower motor resistor module.. 2023 Traverse LT 3.6L 7,500. 2013 Equinox 3.6L 121,000. 2003 Trailblazer 4.2L 188,000. 2010 Traverse 3.6L 193,000.. Mentalup
How to wire a furnace or AC blower motor. This video shows how to wire a furnace blower motor to an extension cord, how to reverse the rotation, what informa...Dec 27, 2014 · # 1 low speed .Looking at a wiring diagram I would think that impossible . # 1 position for low speed would need to go through all the resistors in the resistor pack , which would mean all others good . # 5 high speed doesn't use resistors . uses a relay an direct B+ to the blower motor . Just replaced blower motor resistor to fix fan not coming on. How to test the blower motor resistor 2001 2004 dakota durango. You ll notice that the blower motor is a simple 2 wire component. Dodge was founded in 1914. Variety of 2002 dodge dakota wiring diagram. Cómo probar el motor del soplador 2001 2003 dodge dakota and durango at.First off check for voltage at the connector to the motor with switch in all positions getting anything. Check for damage of the wires in the connector. These cars had a issue with them not being tight and causing high resistance and melting them up. Also, some have found that the connector on the back of the switch for selecting the fan to ...Connect the wire harness to the blower motor resistor… and engage the wire harness connector locking tab. To reinstall the glove box, put it in position and turn it slightly sideways… so...anythingonwhlz Discussion starter · Jan 3, 2012. Happy New Years to all. Im in the middle of trying to figure out why my heater is not blowing. So I figure Id check the wiring on it. So can someone please post a complete wiring schematic of the heater/blower fan set-up from the fuse box to the switch to the fan motor?Product Spotlight: Blower Motor Resistor (RU631) On most full-size GM trucks and SUVs from 2001–2007, the Blower Motor Resistor has two common failure modes: water damage and excess heat. The GM vehicles are unable to manage condensation. If the duct is clogged, condensation will collect, creating a pool of water that can seep into and flood ...BASIC BLOWER RESISTOR WIRING DIAGRAM (POSITIVE SWITCH CONTROL)Panibagong video na naman ang aking nais ibahagi sa inyo mga bossing. So sa video na ito itutur...8.9K subscribers Subscribe 1.6K views 2 years ago how to diagnose fan motor from wiring diagram with blower resistor Network this explains all of the speeds of the fan motor and how the...Jul 10, 2018 · A. adamjeeps · #3 · Jan 4, 2019 (Edited) Jeannecar said: I would like to hear from anyone who has had their blower motor for the A/C go out along with resistor wire melting. I just had this happen at 42k miles so not under way...cost is $850.00 to fix due to blower motor, resistor wire and harness plug. I was told this happens as the blower ... Feb 4, 2022 · The most common causes for AC fan blower motor not working in Ford Fiesta are blown fuse, bad relay, resistor or control module malfunction and faulty blower motor. However, a bad electrical connector or broken wire, or a defect in the climate control unit can also cause the blower motor to stop working. 1. miami5th said: If you buy the Mopar kit with the upgraded resistor you have to swap the wire orientation coming from the resistor to the blower motor. I believe it's a green and black wire set. I just focused on the plug that goes into the blower motor. No need to slice and splice to change the wire orientation.Jun 1, 2013 · In most cases it's the blower motor resistor. Below is a diagram of its location, the plug and how to remove it. Looking at the picture of the plug you will want to turn the fan switch to different settings (the ones that don't work as well) and if you are geting power to each of those conections at the plug but the blower motor isn't turning on, this will be your problem. May 30, 2022 · BLOWER RESISTOR BLOCK WIRING DIAGRAM (NEGATIVE SWITCH CONTROL)Sa video na ito ay ipapakita ko sa inyo ang wiring diagram ng blower resistor block. Kaya't pan... Share. Access our free Wiring Diagrams Repair Guide for GM Firebird 1967-1981 through AutoZone Rewards. These diagrams include: Fig. 1: Common wiring diagram symbols. Fig. 2: Engine control wiring schematic 1967-69 models. Fig. 3: Engine control wiring schematic 1970-71 models. Fig. 4: Engine control wiring schematic 1972 models.Dec 8, 2014 · On my 1066, though, the blower has a similar wiring setup. The three wires from the motor are indeed the speeds. If you put 12v of power to each one in turn, the motor should run at whatever speed you have powered. One terminal on the switch should have battery power. The other may be for powering an air conditioner unit. Sep 17, 2014 · Wiring diagram for 1999 nissan maxima blower switch. Replaced blower motor resistor but fan for heat and ac works on high only. suspect switch is bad. would like wiring diagram for blower motor switch to test switch to verify its bad. Posted by Anonymous on Sep 17, 2014. Nov 16, 2015 · All control of the blower operation is done using the ground side of the circuit. You should always have 12 volts at the brown wire of the blower connector. You won't get 12 volts by metering the brown and orange leads, if the ground is defective. There aren't any HVAC grounds in the ground point on the left side. .