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Brake lights not coming on, but 3rd brake light works

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49K views 14 replies 9 participants last post by  57diesel  
#1 ·
I have a 1995 Suburban 1500 6.5TD with 153 000 miles. I have always thought that when you put your foot on the brake pedal, the rear brake lights light up in the center of the rear tail light cluster. Is this correct?

A few months ago, I was told that my rear brake lights were not working, but the top 3rd light was working. I opened the rear red light cover and checked the bulbs – they were all working. After starting the car, the brake lights started working once again. However, a few days later they stopped working again. I took it in to two car repair places who tried to fix the problem. After the 2nd place looked at it, the brake lights were coming on in the top part of the brake light cluster – i.o.w. the top bulb, not the middle. After a few weeks, the brake lights stopped working again, but 3rd brake light is still working.

I have had two mobile mechanics from craigslist look at the problem in the last few days. They both diagnosed that there is no power coming to the rear brake lights – all the other bulbs work, except the brake lights – turn signals, tail lights and back up lights work. They checked the fuses inside the car and the fuses and relays under the hood – they all work. They said it’s not the brake light switch, as the 3rd light is working. The final diagnosis from them is that my multi function turn signal switch on the steering column has gone bad.

I have 3 questions:

1. Does this sound like the correct diagnosis?

2. If so, what kind of multi function switch must I buy and from where? I called a GM dealer and the want $497 for the part. I checked on line and the same multi function turn signal switch sells anywhere from $45 to $280. They all claim that the parts are made to OEM specs and they all have a 1 year warranty. If I need to replace the switch, do I need to get the most expensive one? Should I get an ACDelco switch even though it also has only a 1 year warranty, but costs 3 times more? The GM part number seems to be 26100985 and the ACDelco part number is D826A.

3. Finally, the mechanics each quoted me $102 and $120 to fit the switch in the steering column, figuring one a half to two hours labor total. From what I have read on line, a lot of stuff has got to come off to fit the switch, including the airbag. The mechanics say you don’t need to take out the airbag – it’s a fairly quick and easy job to do.

I would appreciate some advice and input from the members of this forum.

Thank you very much!
 
#2 ·
Do your 4 way hazard lights work? If they work in the front but not the back it's probably a problem with the rear wiring and not the multifunction switch.

If I remember correctly there's a plug-in style connector in the wiring harness from the fuse block to the rear of the vehicle located near the rear bumper connecting wires to the stop, tail and back-up lights. It's not one continuous wire loom to the lights. That connector might be bad or loose.

A good tech does not have to remove the airbag to replace the switch if it's bad. But certainly pull the airbag fuse anytime you're inside the steering column. I've used two aftermarket multifunction switches without any problem. Here's a site selling for under $50. http://www.sandmansauto.com/catalog...-models-turn-signal-switch-cruise-p-19296.html?gclid=CJqb4NW2v7cCFclQOgod2SkAtA I think I paid about $90 from Rock Auto. ~FH
 
#3 ·
Florida Horseman,

Thank you for your fast reply! My hazard light switch has not been working for months. It does not stay on after I depress it. I just went out to check and if I hold it and gently move it to the left, then all 4 lights will flash - the front and the back.

Do you think this has anything to do with the brake lights not coming on when I depress the pedal? Do you think if I replace the turn signal switch, this will solve the problem?

Thanks also for the names of the two places which carries the parts.
 
#4 ·
It does sound like the MFS is ready for replacement but I'm not 100% sure it will fix the brake light problem. They should be 2 separate circuits. But they may share a connection somewhere because when the 4 ways are energized you should be able to override them when the brake pedal is depressed. Try holding that 4 way button to the left, step on the brake and have someone watch for steady brake lights. You might also know they're working if the turn signal indicators stop blinking and stay on steady with the brake and 4 ways going at the same time. But I'd get a visual confirmation to be sure. ~FH
 
#5 ·
Thank you again Florida Horseman.

You suggested that: "Try holding that 4 way button to the left, step on the brake and have someone watch for steady brake lights".

I did that and there are still no brake lights. I wiggled the hazard light switch backwards and forwards and side to side as well, but that did not work either.

Do you possibly have any other suggestions as to what I can do to resolve this?

Thank you!
 
#6 ·
Other than checking the wire connector under the vehicle where the main loom connects to the tail light harness, I'm out of ideas. ~FH
 
#7 ·
The third brake light is powered directly by the brake switch. The regular brake lights go thru the turn/hazard switch. If turn signals work and you said the 4-ways worked, then you probably do need a new MFS.
 
#8 ·
I had a similar issue and found some of the wiring from the trailer light harness to brake lights were frayed, also check for corrosion in the light socket which is a known failure, also check your fuses, both boxes, 1 under hood and 1 in door jam.
 
#9 ·
Would appreciate the opinion of a few more members of the forum so that I can determine what to do. Thank you!
 
#10 ·
Dude, the people above you are the expert since they have the experience.
Those are not OPINION anymore.

I have opinion because I have never a problem like yours that is why I did not give any input. LOL!!!
 
#13 ·
I have a 1998 gmc sierra k1500 swapped in a low mileage 5.7 engine and 4l60e along with the wiring harness from a 1997 Tahoe for some reason my third brake light is stuck on but my lower brake lights do not work. The taillights and turn signals are working fine I have replaced the brake switch checked all the wiring from front to rear and still no luck. Any ideas??
 
#14 ·
Welcome.
How much of the 97 wire harnesses did you swap to the 98?
What engine did the 98 originally have?
 
#15 ·
Hackery related to trailer lights is always the first place to start looking. I no longer remember the exact details but I do recall on one truck there was a white wire in the harness to the back that was a direct connection to the brake pedal switch that is in addition to all the usual wires back there. I was trying to un hack past issues and my diagram showed a white wire back there as ground so I grounded that wire. It was fine till I had a trailer hitched up at which point that white wire pretty much melted into the rest of the harness.