I cannot figure out what is wrong with this blower motor?

GROUNDED27

MEMBER
1993 CADILLAC DEVILLE
4.9L
V8
2WD
AUTOMATIC
67,000 MILES

I have read about every form I can read I cannot figure out what's wrong with this blower motor. It just does not work it will not come on been dealing with it for over a year. I hooked a toggle switch to the blower motor, and it works on high. I've already replaced the circuit that's hooked to the blower motor that did nothing. The relays that's above the blower motor I took them out and switched all of them around just to see if that was the issue that's not it. I have checked every fuse with a multimeter and I'm not sure what else there is to this system. I can use a test light I can use a multimeter. Where do I start? This is my father's, and the blower motor has been replaced. Help

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,256 POSTS

Since you connect power to the blower motor and it works, it tells us the ground is okay, so that is nice. It sounds like the BCM is not working for this function, but it could be the climate control module on the outside, here are the wiring diagrams for the blower motor so you can see how the system works. I also included the BCM location so you can remove it and send it in for testing.

This guide can help test power and grounds:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the images (below). Please let us know what happens.

Images (Click to make bigger)