blower motor out

pp270 · 01-04-2006, 01:49 PM

I have a 2000 GP GT. I just replaced the heater blower motor, and while driving I heard a poping noise from behind the control unit. The motor then died. I checked all the fuses associated with the motor on the panel and they are fine. Any ideas? Is their an in line fuse to the blower motor that I missed?

BNaylor · 01-04-2006, 03:33 PM

Do you have a manual HVAC control unit or digital climate control?

Did you replace the blower motor resistor (manual) or blower motor control module (digital) when you changed the blower out?

There is a fuse for blower hi-speed position 5.

pp270 · 01-04-2006, 11:41 PM

It is digital and I did not replace the control module. The hi speed fuse was fine. In fact all fuses related to the HVAC in the panel were fine. Do you know if there is an in line fuse? Any help is appreciated.

BNaylor · 01-05-2006, 12:13 AM

Quote:

Originally Posted by pp270

It is digital and I did not replace the control module. The hi speed fuse was fine. In fact all fuses related to the HVAC in the panel were fine. Do you know if there is an in line fuse? Any help is appreciated.

I checked the GM Grand Prix wiring diagrams for you and the answer is there are no other fuses. Only the DIC/HVAC and HVAC HI fuses.

It is then a straight shot from the fuses directly to the climate control unit. From the climate control unit then to the blower motor control module. So it looks like it maybe 50/50 between the climate control unit and blower control module being defective or worse case blower motor again.

richtazz · 01-05-2006, 12:33 PM

On the digital climate control, the control head is more problematic than the blower module. Since both pieces are quite pricey, I'd diagnose further before I start swapping parts though.

BNaylor · 01-05-2006, 12:49 PM

Quote:

Originally Posted by richtazz

On the digital climate control, the control head is more problematic than the blower module. Since both pieces are quite pricey, I'd diagnose further before I start swapping parts though.

That's a difficult area to troubleshoot and just about everyone I worked with had to do some form of controlled substitution to determine if it was the climate control head unit or blower motor module.

Digital climate control systems have a diagnostics mode you can go into which may or may not help but it does generate a two digit DTC error code on the display if there is a fault.

Another suggestion is to yank out the blower motor and apply 12v volts to it to make sure it is still good. I recall for module output the best place to check with a multimeter is at the electrical plug for the blower motor.

To troubleshoot specifc output of the head unit, it requires removal of the dash bezel and head unit.

Either way it could be time consuming and tedious and expensive.

pp270 · 01-07-2006, 03:09 PM

Quote:

Originally Posted by bnaylor3400

I checked the GM Grand Prix wiring diagrams for you and the answer is there are no other fuses. Only the DIC/HVAC and HVAC HI fuses.

It is then a straight shot from the fuses directly to the climate control unit. From the climate control unit then to the blower motor control module. So it looks like it maybe 50/50 between the climate control unit and blower control module being defective or worse case blower motor again.

bnaylor3400 might you be able to provide me with that wiring diagram? My Haynes manual doesn't have one for the digital automatic dual climate control on a 2000 GP GT. It only has one for the 1995. If not can you direct me where I need to go to find one?

I did some voltage checking and this is what I got:

Wires to Blower Motor:
Purple: 0V
Black:0V

Wires to Blower Control Module:
Orange: 11.2V (allways 11.2 regardless of the speed setting)
Black: .08V
Gray:.12-.33V (varies depending on the speed setting)

If I interpret this correctly it looks like the Blower control module is bad since I have power coming into it, but no power going to the motor. I am assuming the gray is the speed control from the climate control. Since its voltage varies I am assuming it is working properly. The digital display on the climate control also works which further tells me it is the blower control.

If you agree it is the blower control do you know how to unfasten it?

Regards,

BNaylor · 01-07-2006, 03:22 PM

Quote:

Originally Posted by pp270

bnaylor3400 might you be able to provide me with that wiring diagram? My Haynes manual doesn't have one for the digital automatic dual climate control on a 2000 GP GT. It only has one for the 1995. If not can you direct me where I need to go to find one?

I did some voltage checking and this is what I got:

Wires to Blower Motor:
Purple: 0V
Black:0V

Wires to Blower Control Module:
Orange: 11.2V (allways 11.2 regardless of the speed setting)
Black: .08V
Gray:.12-.33V (varies depending on the speed setting)

If I interpret this correctly it looks like the Blower control module is bad since I have power coming into it, but no power going to the motor. I am assuming the gray is the speed control from the climate control. Since its voltage varies I am assuming it is working properly. The digital display on the climate control also works which further tells me it is the blower control.

If you agree it is the blower control do you know how to unfasten it?

Regards,

Send me a PM email with your email address and I'll send you the relevant wiring diagram in jpeg image format attachment. I'll need to scan the page from the service manual in first.

BNaylor · 01-07-2006, 03:59 PM

Diagram sent and here is a pic of the Module - AC Power (blower motor control module). I recall there were at least three screws securing it. Only one has to be removed. The other two just loosened and then you can pull the module. Good luck!

pp270 · 01-07-2006, 04:28 PM

Do you know where I can purchase this module? Also the approx cost?

BNaylor · 01-07-2006, 04:43 PM

Quote:

Originally Posted by pp270

Do you know where I can purchase this module? Also the approx cost?

On that part I am quite sure it will be dealer parts only. Cost is around $100. Expensive compared to the cheapy blower motor resistor on manual HVAC systems which only costs around $25. Also, you might look for a local authorized AC Delco parts dealer/auto parts store which have better prices than the dealer.

The AC Delco part number is 15-8756.

Another option is to see if you can get one at a salvage yard off a Grand Prix or Regal that has auto digital climate control. This is the cheapest route. The module for the Grand Prix and Regal are the same to include some other GM "W" body cars. Good luck!

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