Ac - Heater Blower Motor Not Working

knightgang · October 20, 2010

I have a 2001 Chevy 1500 HD, 4x4, 6.0 ltr with Auto Climate Control. Everything was fine one day and the next, the blower motor would not work. I usually leave the AC on, either on Auto or with the fan control about 1/2 to 3/4 the way turned up. On this particular day, someone else drove my truck and the turned off the AC using the Fan control knob turned to off. When I got in and turned the AC back on, the compressor kicked on, but the blower motor would not work. After several days of trying to trouble shoot, I finally straight wired the blower motor with a switch to get through the summer, now I need to fix it before it gets cold so that I can have heater. Here is what I have done, tried so far.

1st thought was the blower motor module was bad. Bought a brand new one off of E-bay. No dice, motor still not working. (Again, with 12V direct it works just fine).

2nd, tested the voltage at the plug that goes into the blower motor module. I get 12v across the orange wire and the black wire, then I get .01 to .05 volts across the black and the grey/white depending on the position of the fan control switch.

3rd, with the blower motor plugged in and testing at the plug that goes into the Blower motor, I get .08 volts ragardless of fan switch position.

4th, I have disassembled the AC Control head and cleaned inside the fan control switch, no change.

At this point, I feel like the control head is bad, but at $135 new (cheapest I can fine) or even $85 used, I want to be sure that is the problem before I spend the money. Is there any other advice you have for me or other testing to be done to be certain it is the control head that is bad. Bear in mind, all other functions work just fine, blend door, Fresh air/Recirculate, Vent/Defrost deflector door, etc. Only the blower motor will not work while plugged in to the system as it should be.

Please help...

darwyn · October 30, 2010

I have a 2001 Chevy 1500 HD, 4x4, 6.0 ltr with Auto Climate Control. Everything was fine one day and the next, the blower motor would not work. I usually leave the AC on, either on Auto or with the fan control about 1/2 to 3/4 the way turned up. On this particular day, someone else drove my truck and the turned off the AC using the Fan control knob turned to off. When I got in and turned the AC back on, the compressor kicked on, but the blower motor would not work. After several days of trying to trouble shoot, I finally straight wired the blower motor with a switch to get through the summer, now I need to fix it before it gets cold so that I can have heater. Here is what I have done, tried so far.

1st thought was the blower motor module was bad. Bought a brand new one off of E-bay. No dice, motor still not working. (Again, with 12V direct it works just fine).

2nd, tested the voltage at the plug that goes into the blower motor module. I get 12v across the orange wire and the black wire, then I get .01 to .05 volts across the black and the grey/white depending on the position of the fan control switch.

3rd, with the blower motor plugged in and testing at the plug that goes into the Blower motor, I get .08 volts ragardless of fan switch position.

4th, I have disassembled the AC Control head and cleaned inside the fan control switch, no change.

At this point, I feel like the control head is bad, but at $135 new (cheapest I can fine) or even $85 used, I want to be sure that is the problem before I spend the money. Is there any other advice you have for me or other testing to be done to be certain it is the control head that is bad. Bear in mind, all other functions work just fine, blend door, Fresh air/Recirculate, Vent/Defrost deflector door, etc. Only the blower motor will not work while plugged in to the system as it should be.

Please help...

I've had pretty much the same issue when I got my 05 silverado 1500. Go here to get the answer... and parts if you want.

http://www.sparkys-answers.com/2008/07/200...lower-inop.html

smac76017 · January 20, 2011

I have a 1999 Silverado and had the same problem and just fixed it today. Try disconnecting the blower motor switch and Check for power with a test light at CKT 141 Brn wire first with the key in the run position. If you have power start checking for continuity between the blower motor switch and the blower motor resistor with an ohm meter, orange to orange purple to purple etc between the 2 connectors. Let me know what you find out.

Sean