Brake and HVAC problems connected?

Tiny
SUMANULA
  • MEMBER
  • 2005 CHEVROLET TAHOE
  • 5.3L
  • V8
  • 4WD
  • AUTOMATIC
  • 209,000 MILES
At first the brake and ABS lights would randomly come on, it has the tow package and hydra boost brake system, stay on a short time and go off while driving. Two days ago, they came on and stayed on the rest of the day. I checked the fluid level and the park brake switch, the fluid was good, and the switch is open with the pedal released and closed with the pedal set, pushing and releasing the park brake pedal does not affect the red brake light at all. I disconnected the battery for a while, probably half an hour. When I reconnected the battery all the lights were out on startup, about 10 seconds after startup, did not touch the brake pedal, both the ABS and Red Brake light came on and I noticed for the first time, the front blower motor quit at the same time. After a few more times, I can tell you both the front and rear blower motors quit at the same time, 5 to 10 seconds after starting up, as the lights come on. Now, even after resetting the battery, the lights come on with the key on and don't ever go off. Couple parts stores tried to get the ABS codes, but it would not communicate with any of their scanners. The only code found was in the SRS U1000.
I've cleaned all the grounds I could find and checked all the fuses. It feels like the two systems are somehow sharing this problem and that points to? The Body Module? Or am I nuts?
Thursday, July 3rd, 2025 AT 4:33 PM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 52,648 POSTS
The ABS and blower motors have nothing to do with each other. The ABS will have no codes because the system is operating normally, the lights go on when the front ABS can't read because of the bearing hubs going out and the sensors lose readings which lights the warning lights. The way to fix it is to replace the hubs, here is a video to show you how:

https://www.youtube.com/watch?v=ZgiPRG6jffc

I would do both fronts. Start a new thread for the blower motor issue. Let us know how it goes.
Was this
answer
helpful?
Yes
No
Friday, July 4th, 2025 AT 6:12 PM

Please login or register to post a reply.