How To: Blower Motor Resistor replacement for GMT400s

[07Burb]

This is for the late model gmt400 trucks. May also work for the 88-94 but not 100% sure if they are configured the same but could be

This is to fix the issue of the HVAC controls only working on select fan speeds (if at all). So let's get to the steps and the pics.

1. Clean out glovebox


2. Remove glove box


3. Locate the resistor on top near the back.

4. Use a flat blade screwdriver to GENTLY get the connection disconnected from the old resistor


5. There are two 7mm screws holding the resistor down. Unscrew those. It also helps to swing that relay out of the way that's on the left

6. Work out the old resistor then reverse the process. It's not hard but does take some patience


Old vs new

 

[Johnny Racer]

Just had to do thy to mine about 2 months back. Really easy actually. I removed my relay which made it easier. Kinda tight in there. The bolts holding it in are 7mm BTW. Don't forget to install the new supplied gasket on the new one before you install it. No to replace the noisey blower motor itself.

 

[07Burb]

Yep I stated 7 mm up in step 5 and I figured the gasket thing was self explanatory lol