2005 Envoy Blower Not working---help!


graveszee
09-22-2007, 02:15 PM
I have a 2005 Envoy and the blower isn't working on any speed. I have checked the fuses, they are good. Also have voltage right up to the motor plug in. Now, where is the resistor? I unpluged the plug in from the motor but don't see a resistor. The female plugin mounted to the motor doesn't seem to be removable. Could the resistor be built inside the motor?:banghead:

envoyxuv
09-22-2007, 02:33 PM
First, a question: are your heating and air conditioning controls automatic (bright blue digital display) or manual? Manual has two sliders- one for the driver and one for the passenger to adjust their temperature individually.

If you follow the two wires you unplugged from the motor back to their origin, you will find a rectangular black box screwed to the HVAC case with two gold colored 7/32" screws. If your heating and air controls are automatic, there will be a three-wire plug connected to this black box. This would be called the blower motor control processor. If you have the manual heating and air controls, it will have a seven-wire plug connected to this black box, and is a resistor.

graveszee
09-22-2007, 05:06 PM
It is a manual not automatic. I pulled the blower motor, it runs fine when hooked direct to the battery. Tested the two wires on the motor plug in. Got 12.3 v on settings 1-4 dropped to 11.6v on setting 5. Plugged the motor back in turned on setting 1 it turned about 3/4 of a turn then stopped. So does this still sound like the resistor? Thank you for your earlier reply.

envoyxuv
09-25-2007, 09:33 PM
So you verified the motor works. That's a good start. Now you want to check the voltage going to the resistor to make sure there isn't an issue between the manual fan switch and the resistor. You can do this easily with a 12-volt test light or a voltmeter. i prefer a test light because it is visual confirmation, and easier than using a voltmeter in this situation. Use the following info as a guide:

Red wire, pin G should have constant power. orange wire, pin f shoud be speed #5, purple wire, pin c should be speed #4, light blue wire, pin d should be speed #3, tan wire, pin a should be speed #2, and yellow wire, pin b should be speed #1. The black wire is ground. Each wire should light up the test light when touched when the corresponding speed is selected on the fan switch.<If all of the speeds light up the corresponding wire at the connector, that means the resistor is getting all the right signals and has an internal fault and should be replaced.> If you find the connector won't unplug or is melted, GM has an updated connector as a fix and the resistor and connector should be replaced.

graveszee
12-21-2007, 12:19 PM
So you verified the motor works. That's a good start. Now you want to check the voltage going to the resistor to make sure there isn't an issue between the manual fan switch and the resistor. You can do this easily with a 12-volt test light or a voltmeter. i prefer a test light because it is visual confirmation, and easier than using a voltmeter in this situation. Use the following info as a guide:

Red wire, pin G should have constant power. orange wire, pin f shoud be speed #5, purple wire, pin c should be speed #4, light blue wire, pin d should be speed #3, tan wire, pin a should be speed #2, and yellow wire, pin b should be speed #1. The black wire is ground. Each wire should light up the test light when touched when the corresponding speed is selected on the fan switch.<If all of the speeds light up the corresponding wire at the connector, that means the resistor is getting all the right signals and has an internal fault and should be replaced.> If you find the connector won't unplug or is melted, GM has an updated connector as a fix and the resistor and connector should be replaced.

I replaced the blower motor resistor and everything worked again. But now, it has stopped working less than 3 months after replacement. Just before it stopped working the headlights would dim down and then the blower motor would stop working. I would hit the brake and the motor would come back on (not sure if that had anything to do with it or not). Any suggestion on what to try now? I am freezing with no heat.

graveszee
12-21-2007, 12:31 PM
Also, does anyone know of a gm web site that I can order off of. I paid 60 bucks for this resistor at my dealer.

maxwedge
12-21-2007, 03:15 PM
Really, I paid 31.00 3 months ago. GMPartsdirect.

drewsr1
02-21-2008, 08:50 PM
If you look at the wiring plug of 7 wires going into the regulator you will see there has been some melting. I have the same problem and the dealership said they change them all the time. Both sides melt and then loose contact. There must be to much amperage going through it on high speeds.

Timoh47
12-19-2008, 05:47 PM
I'm having the same issue with my 2005 Envoy. About a week ago headlights, and interior lights kept dimming on my ride home, next day all seemed to be fine.

Tonight the blower won't work on any speed or heat/defrost/AC setting.

maxwedge
12-19-2008, 07:58 PM
Guys this is year old thread start a new one thanks.

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