Brake lights not working

Tiny
SSTEVE694
  • MEMBER
  • 2005 CHEVROLET SILVERADO
Electrical problem V8 Two Wheel Drive Automatic 32500 miles

my brake lights do not work, but the cab brake light does. The flashers will work and turn indicators also. So I know its not in the fuse, and changed out both bulbs.

Just found out a few days ago. Brake lights do not work but all other signals and the cab brake light works.

Tested everything, switch is fine, receiving power to the fuse panel under the hood and in the cab fuse. Grounds look good, bulbs good. No visible wiring issues.

What would you recommend as a way to test the switch? I have spend 8 hours testing every wire in/out of the turn switch and the fuse panel to no conclusions. I tried jumping across the switch itself to no success. Tried unplugging it to no success.

The white(brake power) is good coming out of the switch going into the fuse panel and into the turn lever itself. The CM brake light tests good. The rear brake fuse jumps up and drops back down to zero on the multi meter. Testing the backside of the fuse panel blue wire tests good 12v when pressing the brake pedal which is odd. From the wiring diagram all this doesn't make sense. I am looking for a way to make sure its the switch itself before purchasing one. Any ideas would be appreciated.

Anyone figure this out yet?
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Saturday, April 19th, 2008 AT 8:02 PM

81 Replies

Tiny
KEN
  • ADMIN
Hey guys,

There is a fuse that runs just the lower brake lights, here is a guide and some wiring diagrams to help you trace the problem down. Check to see if there is power at the brake lights to see if the problem is a ground issue.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/brake-lights-not-working

Please run some tests and get back to us.

Best, Ken

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Saturday, January 21st, 2017 AT 3:12 AM
Tiny
JSCHEVY
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 50,000 MILES
Electrical problem
2005 Chevy Silverado V8 Two Wheel Drive Automatic 50000 miles

The brake lights on the bed are not working. However the brake light on the cab is working. I replaced the bulbs and I checked the fuses, but that was not it. I looked at your wiring diagram and noticed the park lamp relay was in the circuit so I replaced it and now ti all works.

Here is the relay on Amazon

https://www.amazon.com/gp/product/B000C9Q19I/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=2carprcom-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B000C9Q19I&linkId=d7e970874009393e5c9b8c95edaec423

Thanks for this site, it rocks! :)
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Saturday, January 21st, 2017 AT 3:14 AM (Merged)
Tiny
JAMES W.
  • MEMBER
First question I always ask is; do you have a trailer connector spliced in behind the bumper? 75% of the time, that's where the problem is. Please advise.
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Saturday, January 21st, 2017 AT 3:14 AM (Merged)
Tiny
JSCHEVY
  • MEMBER
I believe I have one but it is factory installed. Does that make a difference? And, what in particular would be the problem there, a short or is there a fuse there?
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Saturday, January 21st, 2017 AT 3:14 AM (Merged)
Tiny
JAMES W.
  • MEMBER
You will want to test your trailer connector to see if you have brake lights there. You're looking for an "open" in the circuit somewhere. The brake light switch has to be functioning or the cab light wouldn't be working.


http://www.2carpros.com/forum/automotive_pictures/248092_brake_lights1_1.jpg



http://www.2carpros.com/forum/automotive_pictures/248092_brake_lights2_1.jpg



http://www.2carpros.com/forum/automotive_pictures/248092_brake_lights3_1.jpg

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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
JSCHEVY
  • MEMBER
I tested the harnesses that adjoin on the connection block. I get main power coming in. However, when I test the brake connections, no power. I have power to my tail lights, blinkers and all, which look to be coming from that block as well. A parts guy said that usually those blocks go out on one full side, which sounds to me like if it was the block then I would have either the right or the lefts side lights out. You said that it could be an open, but I don't know where to test it to find out, because I am not getting power to my brake lights from that block. What suggestions do you have?
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
JAMES W.
  • MEMBER
You're right, the chances of both sides going bad are poor to none.
Let's start from square 1. We'll be testing at the socket for the "turn signal flasher module", under the left side of the dash. The brake lights go through this module.
The brake lights are fused seperately from a 25amp fuse(# unknown) in the underhood fuse block. This fuse should be hot all the time.
Fuse good, yes, test the orange wire at brake light switch.
Orange hot, yes, push the brake pedal and test the white wire on the BL switch.
White hot, yes? Test the white wire at the flasher module, terminal B, with brake pedal pressed.
Hot, yes?, check fuse #9 in fuse block by flasher module.
Fuse good?, yes, check the junctions and connections on the light blue wires going back to the brake light lamps.
Fuse #9 should be hot when the brake pedal is pressed.Let me know what you find.


http://www.2carpros.com/forum/automotive_pictures/248092_05_silverado_flasher_1.jpg

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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
ROBERT GLENN FRANCIS
  • MEMBER
Well It's now the end of April 2016 and my chevy silverado 3500 has a similar issue. Everything works except the bed lamps for the brakes. I hooked up the boat trailer and all checks out perfect. It's the twighlight zone issue. I can not find fuse #9 because the label on the lid does not show numbers for the fuses. I wish I could understand the schematics better but my studied discipline is in another field I can only get close at best. Any help would be most appreciated.
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
DVIDOR88
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 88,000 MILES
Electrical problem
2005 Chevy Silverado V8 Two Wheel Drive Automatic 88000 miles

My brake lights are not working. I checked the fuse and the bulbs, both are fine. Could there be a disconnect somewhere?
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
FRED@SMITH-COMPANY.COM
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 33,000 MILES
Electrical problem
2005 Chevy Silverado V8 Four Wheel Drive Automatic 33000 miles

One brake light does not work. All fuses are ok but left brake light does not work. I put in a new bulb & fuse but nothing.
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
MASTERTECHTIM
  • MEMBER
Take a close look at the tail light socket, make sure it does not look like it is melted at all. You might have a bad socket
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
SCOOPMAIL
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • V8
  • 2WD
  • AUTOMATIC
  • 50,000 MILES
Electrical problem
2005 Chevy Silverado V8 Two Wheel Drive Automatic 50000 miles

My brake lights on my bed do not work, but the cab brake light does. The flashers will work and turn indicators also. I know its not in the fuse, and changed out both bulbs
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
WRENCHTECH
  • EXPERT
That is likely a bad Combination switch in the steering column. Both lower lights run through it so the turn signals can cancel the brakes lights when necessary. It's a pretty common failure.
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Saturday, January 21st, 2017 AT 3:15 AM (Merged)
Tiny
RCCOMPTON
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • 5.3L
  • V8
  • 4WD
  • AUTOMATIC
  • 100,000 MILES
Cab brake light and passenger rear brake light work but the driver rear brake light doe not. I replaced the bulb (the bulb works because when I use the key fob to unlock the truck the top rear brake light lights up). I thought I read on the internet that the light blue plug/connector going into the junction box was for the driver side brake light so I disconnected it and inspected it and no corrosion (California truck). I sprayed electronic cleaner on both the plug and junction box and reinstalled and it worked. Then the brake light came on when brake pedal was applied. Later in the day the brake light quit working again. I went through the same process again and it hasn't worked since.

Thank you in advance for your help,
Unemployed Robert
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
HMAC300
  • EXPERT
Check the ground at rear of frame by junction box and then make sure the wires are pinched at top
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
MAXIMILIAM
  • ADMIN
Thank you for your prompt response. However, regarding my 2005 Chevy
Silverado I do not see a ground wire-everything is routed through harnesses.
Did you mean checking the ground (maybe one of the other plugs that plug
into the junction box?) As part of the junction box?

Thank you in advance,

Robert Compton
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
HMAC300
  • EXPERT
It'sont eh left rear frame like I said in first reply
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
TRUCKGUY1016
  • MEMBER
  • 2005 CHEVROLET SILVERADO
  • V8
  • 4WD
  • AUTOMATIC
  • 85,000 MILES
Electrical problem
2005 Chevy Silverado V8 Four Wheel Drive Automatic 85,000 miles

The Brake lights on the bed dont work, also the trailer connection isnt working. My third brake light works though) I replaced the bulbs in the tail light assembly. And checked the old bulbs but they work fine. I checked the fuses under the hood and in the dash. Dash-good. Underhood-bad. So I replaced the one under the hood. The one in the dash says "VEH STOP" and the one under the hood says "TRL PARK" (the new one hasnt blown) ok, Thinking I had the problem fixed ! But nope! I came on this site and found a trouble shooting guide step by step. Ok thought I had it now. I followed each step and found I had power to both fuses, the brake light switch(on the orange, and the white) I have power all the way through the check list till the last step. When I check I have no voltage coming through the light Blue wire at the tail light. I crawled under the truck and followed the harness back all the way to underneath the cab. I peeled back the plastic protective sleeve, and fanned out the wires. I stripped off a tiny piece of the jacket on that light blue wire, and checked the voltage. ( With the brake off, and with it depressed- nothing. Any help would be greatly appreciated ! I fear it is a bad wiring harness, But like I mentioned, I have parking lights, back up lights, turn signals, just no brake lights.
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
INTERNETMECHANIC
  • MEMBER
I couldn't do any better than your doing, I'd have to backtrack the circuit. There appears to be a junction for the fuse circuit at the underhood fuse box. Lite blue wire, E7 in the diagram. That circuit comes from the stop fuse.


http://www.2carpros.com/forum/automotive_pictures/512072_silverado_brake_lite_1.jpg

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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)
Tiny
02REDCAMARO
  • MEMBER
I had a similar problem with a 96 Silverado with a fiberglass topper. Problem I found was a bad ground that someone had done when they wired up the third brake light and interior dome light on the topper. I found the bad ground on the rear frame rail where the topper installer decided to terminate it.
I'd look underneath the box for some non-factory wiring, and check and clean the termination points.
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Tuesday, April 18th, 2017 AT 12:23 PM (Merged)

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