FAQ Library

Low blower speeds don't work!

This common problem is related to 3rd generation J-bodies. It is not unheard of for this to happen several times during the lifetime of your car.

SYMPTOMS
Typically, speeds 1 and 2 (the two lowest speeds) of your HVAC blower fan stop working. Speeds 3 and 4 would continue to work.


DIAGNOSIS
Replace the Blower Resistor (GM part #52476725).


REPLACEMENT PROCEDURE
(reference: GM J-Platform Shop Manual)

Removal Procedure
(it is recommended that you disconnect the negative battery terminal prior to doing any work on the elecrical system of any car)

Now, in some cases, the left instrument panel insulator might be in the way. If it is, remove it before starting.

1. Locate the blower motor - you have to stick your head under the passenger side dash to see it.

2. Disconnect the electrical connections at the blower motor.
(see figure 1)

3. Remove the blower motor retaining screws.
(see figure 2)

4. Remove the blower motor and fan assembly.

5. Disconnect the electrical connection at the blower resistor.
(see figure 3)

6. Remove the blower resistor screws.
(see figure 4)

7. Remove the blower motor resistor.

Installation Procedure

1. Install the blower resistor. Tighten the screws to 1 N-m (9 lb in).

2. Connect the electrical connector at the blower resistor

3. Install the blower motor and fan assembly. Tighten the blower motor screws to 5 N-m (44 lb in).

4. Connect the blower motor electrical connector.

5. Reconnect the negative battery terminal.


FAQ

What is the Blower Motor Resistor and how does it work?
The blower motor resistor is used by speeds 1 & 2 of your HVAC blower fan. It reduces the current for those speeds in order to slow down the blower fan motor. (I'm not an electrical engineer - but I think that's about as simple an explanation as you can get).

One of the screws in the back is hard to get to.
Persistance is key. I found that using a combination of a small ratchet and a small wrench got the job done. It takes a while, but it works. Some have used flexible ratchet/screwdriver extensions that can bend around to get it.

Can I just repair the damaged resistor?
Some have tried. Some have been successful. But this is not recommended. The resistor is designed to be cooled by the airflow in the duct. Modification to the resistor could result in unwanted heat - and possibly fire.

The replacement resistor is expensive! Can I get it anywhere else?
Currently there are no known aftermarket resistors that would work.

Can I make my own resistor?
Not recommended - although many have tried. It is far easier (and safer) just to fork out the cash and get the right part.

Print Article

Created: 02-11-2005
Modified: 02-14-2005
Rating:

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Replies

Re: Low blower speeds don't work!
Friday, January 20, 2012 7:14 AM
At this late date the resistor is available in after market. Auto-zone for $25. with life time warranty.

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