2008 Silverado brake light issue

Marvin Damartian · August 7, 2014

I also posed this question in the introduction forum. I hope this double post isn't frowned upon. If so I apologize in advance.

Hey All, Im stumped. My 3 brake lights (2 tail lights and 3rd bed light) stay on as if I am stepping on the brake all the time. They will not default to daytime running light. I disconnected harness from brake switch at the pedal and they still stayed on as if I was pressing on the brakes. I removed the fuse and the tail brake lights went out or were only illuminated at normal daytime running brightness. But of course with fuse out I lose turn signals as well. BTW...All turn signals and hazards work normally with fuse in. Its just the brake lights are stuck in full illumination with or without brake switch harness being connected. Does this sound like a short to ground? Perhaps that is why they will not go out? Just in case anyone is wondering the lights will go out when I shut the engine off. It only happens when engine is running.

Thanks in advance for any feedback.

Newbie

Marvin Damartian · August 13, 2014

Well all, it pays to use an OEM part. I went through two aftermarket brake switches of the same type from RS Strouse. Neither worked and and I am taking them back. I installed the ACDelco part and it worked perfect. Thanks for your input.

God Bless,

Marvin

bossier62guy · August 8, 2014

Without the luxury of being able to see a wiring diagram for your truck, there is no way they stay on with the brake switch disconnected unless the connector has overheated at some point and the wires are making contact all the time. Check that connector closely.

gmtech4 · August 11, 2014

you need a schematic in a bad way to self diag this

cobrajet84 · August 12, 2014

I learned when replacing brake light switches that brand does matter, Got two BWD brand ones from Oreilly's auto parts that made my issues worse, so went to the dealership and bought an AC delco and fixed the problem instantly and was actually a few bucks cheaper. It's a place to start if you have tried the same brand twice, but it sounds to me like there maybe an issue in your wiring somewhere.

Marvin Damartian · August 7, 2014

*crickets* Is this an issue too involved or out of the norm?

Duelin · August 9, 2014

*crickets* Is this an issue too involved or out of the norm?

Yes out of the norm. Has there been any after market electrical accessories installed in the vehicle?

Marvin Damartian · August 12, 2014

Thanks Cobra, your reply isn't the first time I heard of this in reference to using an OEM for the brake switch. I used the convenience of going to an auto parts store 3 miles from my house vs 10 miles to the closest dealership. This will be my next move. If resolved I will post just in case others ever have this issue.

cobrajet84 · August 13, 2014

Glad you got it worked out.

txab · August 14, 2014

Well all, it pays to use an OEM part. I went through two aftermarket brake switches of the same type from RS Strouse. Neither worked and and I am taking them back. I installed the ACDelco part and it worked perfect. Thanks for your input.

God Bless,

Marvin

BINGO!

Duelin · August 14, 2014

Marvin Damartian · August 12, 2014

Well last night I went back to the place where I purchased a brake switch and swapped out for a new one. Still has not corrected but believe it or not the situation changed. I noticed without the brake switch hooked to the pedal everything worked as it should. I could manually push in the switch and it would work good. However once I reinstalled the switch the third brake light (bed of truck) would stay on even with engine off. I am starting to wonder if the switch isn't sitting correctly against the plunger of the brake pedal. At my last state inspection they put new brake pads on which tightened the brakes. Is there a way to adjust the plunger that goes through the fire wall? Perhaps ease up on the tension slightly?

gmtech4 · August 8, 2014

no one has replied because it makes zero sense ,,,,good luck

Marvin Damartian · August 11, 2014

No electrical accessories and I know it doesn't make sense. I am wondering if there is a relay somewhere that is stuck? I say that because the brake lights stay fully illuminated even when the brake light switch is disconnected from harness. I looked under the hood for a relay but there isn't one for the brakes. I know car wiring is completely different but I have been an industrial electrician for 30 years. So I am not completely clueless when it comes to troubleshooting. This however has me baffled. I was hoping someone had an idea.