Hello all.
I am new to this forum and I'm in a bit of a bind. Yesterday I was cleaning my car while enjoying some music and lost track of time. I ran my battery dead and had to jump start so i could get things done. While driving I noticed my heat was not properly working, the display read the fan was on and all was fine. I have been researching and conducting tests for the last few hours and I have come to the conclusion that the issue is not with the blower motor itself.
First I checked the cabin air filter for debris, it was clean. Next I checked the rear fuse block and crossed my fingers, all fuses were good and intact. I then removed the kick plate to gain access to the blower, turned the air on high, and tapped it several times with a screw driver handle.. still no luck. I don't have a volt reader, so I used my test light to check the purple power wire, it was hot. I then checked the black ground wire and i couldn't get it to ground out.
Based on these facts, I'm told it could be the blower control module.. not the blower motor itself. Does anyone know where the BCM is and how to diagnose it? Or, has anyone had the same issues I have had and know how to fix it? I'm in Des Moines, Iowa and its 35 degrees out, way too cold to not have heat..lol.
Thanks!

Easiest way to test the blower control module is to put power directly to the blower motor with it unhooked from the electrical of the car.

If it turns..your motor is good. I think you'll find that your motor is bad.

*** update - After further testing both the control module and the motor are both working perfectly, does this mean the main control is causing the issues? Anyone know how to test it?

Were you able to diagnose what was wrong after verified the motor and BCM were alright? My blowers quit working this afternoon. I am just about to go down to the car now to start testing it. Any information would be greatly appreciated! thanks

I just finished working on the Bonneville. In my case, it is the blower motor. I took the advice, and as soon as I hit the blower motor with a screwdriver, it started right up. I took it out of the car and took the back off. There was a lot of junk that fell out of the case. It appears that the brushes and the stator in the motor are worn down. I cleaned it up real good and put it back together and it seems to be working. I am going to try to get a new one in the meantime. Has anyone found somewhere to get one other than the dealer?