Any help would be greatly appreciated. I have a 2004 Trailblazer with 87,000 miles. A few months back, we noticed my brake lights were on in the morning even though the car was not on. If we pulled the brake pedal forward, it would turn the lights off. My battery started to die on me occasionally, rendering the vehicle unreliable. My husband would jump the car and put a battery charger on the car and that seemed to help. He did this 5-10 times. At the same time, the rear HVAC control module started clicking in the right rear of the truck. I didn't worry about that because it is still nice here but I planned on fixing that before summer. The battery continued to drain. Going through batteries is not uncommon in Arizona so I replaced it. THEN the HVAC system was all messed up, some floor and defrost vents working, driver and passenger vents didn't. We took it to a mechanic, telling him all the problems, he said $1200 for all actuators, 8.5 hrs labor. Of course I squacked once I researched my problem on this blog. I knew he was over charging me. When I picked up my unrepaired car unexpectedly from him, he had my fuse box apart. Hmmm. Then I drove away and the car was miraculously healed! Air blowing everywhere it should. Crook was going to screw me for sure! Today I woke up with the brake lights sticking again. I am thinking.... The brake lights stick causing the battery to drain, the battery drains and messes with the actuators. Is that right? If so, how to I fix the brake light problem? Remember, I am a girl... Any photos or video is appreciated.
Brake light problems, dead battery, HVAC actuators, OH MY!!
- Thread starter onesmartcookie
- Start date
You've come to the right place.onesmartcookie said:
Classic misadjusted brake light switch. You could have simply adjusted it then or pulled the brake light fuse to stop the draining.
That tends to kill batteries if they weren't already half gone. Better to pull the offending fuse.
Classic.
It's almost never ALL actuators.
Probably did a good HVAC reset by the disconnection.
Exactly.
Brake light switches are almost always easy to adjust with a threaded housing to rotate to move them in and out. Sorry, I don't recall anybody posting a picture, but it's obvious when you get down there.
Mrs. Roadie says your gender is irrelevant to the question. If you can use tools and read a manual, fix it yourself, otherwise get a friend who does (male or female) to help. I never want to read about females using their gender as an excuse for inexperience they can cure with education.
I have to point out Mrs. Roadie is a bra-burning libber from the 70's who kept her own name and married me anyway 38 years ago, after fighting in the trenches for women's rights back when they had a lot fewer than today.
Just mentioning the girl thing because sometimes explanations get a bit too technical. I am actually the handy one in this family with the cars, home repairs, plumbing. I will figure this out, with the right direction, of course. Thanks!!! I will post my results...
onesmartcookie said:
I see you know me. My explanations get too technical for some electrical engineers at times, I have to admit. 
It's just that I've been conditioned to react to the word "girl" by Mrs. Roadie. She also gives good rant. 
I have removed the access panel and can see the switch. GM part #15163032.
How would I adjust it? Would replacement be easier? It is in a tight and confined location with the steering column in the way. I took photos but was having a heck of a time trying to attach them.
How would I adjust it? Would replacement be easier? It is in a tight and confined location with the steering column in the way. I took photos but was having a heck of a time trying to attach them.
I see from rockauto.com that it looks like this. Not sure how to adjust it. SURELY somebody here has done it before. (That's a HINT, guys...)
View attachment 19945
View attachment 19945
Attachments
RayVoy
Member
- Nov 20, 2011
- 939
Damn hard to respond to a "locked" thread, haha.the roadie said:
The switch has been superseded by part # 15128874
But........... I can not see any adjustment. Might have to crawl under the dash tomorrow to check it out (the same switch is used on the GMT900 trucks as well).
I will tackle this tomorrow. Until then, I will pull the fuse. #34, right? Don't you think it is strange that the lights go on at night when the temperature drops? Have you ever heard of that? Why would that happen? Thanks for all your kind assistance. You don't know how valuable you are.
Voymom
Member
- Feb 3, 2012
- 2,523
onesmartcookie said:
These trucks seem to be extremely moody with cold temps, at least that has been my experience so far. And from one woman to another, Welcome aboard!! I catch a lot of flack from my husband and other men when I roll out from under the truck. For some reason a lot of men (not here) but in general think that a woman can't possibly know anything about cars and mechanics. Shame on them lol
Good luck with your sticky truck. Wish I could be more of a help but I have never heard of the brake lights coming on overnight. Maybe it's just trying to keep warm?
There isn't a whole lot of indepth info on removing the switch. The fact that lifting up on the brake pedal causes them to go off is suggestive of a faulty switch. If you search on Amazon for p/n 15128874 it will return a hit on AC Delco D891A. It's about $18 and if lucky, Amazon's Phoenix warehouse will stock it and you'll have it in a couple days. I could post a picture of how to remove but it isn't very helpful.
I replaced my brake light switch today. How easy and fun!!! I am so proud of myself! My next job will be to tackle the rear HVAC actuator. Who needs a mechanic anymore! Thanks GMTNation!!!
AbsoluteZero said:
I took off the 2 panels under the steering wheel, removed the heater duct and was able to get pretty good access to the switch. The hardest part was the unusual clip that attached the switch to the pedal. I used a screwdriver to pry that off, being careful not to bend it. I then wiggled the switch off and disconnected the 6 prong connector that attaches to the top of the switch. Easy peasy! The part cost $13 plus tax at my local Autozone and they had it in stock.
A good find.... now the proof will be tomorrow when you get up and no brake lights.onesmartcookie said:
I had checked Oreillys but didn't appear to have anything stocked. Never checked Autozone. I often gravitate to mail order during the summer months when we are at the cabin. It's 80-110 mi. roundtrip to Payson or Winslow for parts so I tend to use a mail order source.