Brake lights will not work?

Tiny
JOHN---G
  • MEMBER
  • 1994 CHEVROLET TRUCK
Left rear blinker/brake light wont work. New bulb did not work, another new bulb did not work. Switched rear bulbs - left wont light right still works. All other blinkers work. Meter on left rear socket shows about 11volts, same on right. Meter shows pulses of blinker on both sides. Put red probe of meter on contact inside socket and touched outside socket or inside and it reads about 11 volts. Put wires of new socket on contact inside socket and ground and would not light on left but same procedure works on right. Crimped socket a little to hold bulb tight - no go. Strange problem --- what do you think?
Tuesday, June 16th, 2009 AT 7:24 PM

32 Replies

Tiny
DR LOOT
  • MECHANIC
  • 2,311 POSTS
If you have replaced the light socket and it is still the same that's not the problem, the problem is probably in the wiring coming out or going to your trailer light socket on the bumper. This guide will help us fix the problem

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

Here are the brake light and blinker wiring diagrams so you can see how the system works. Check out the diagrams (Below). Please let us know what you find. We are interested to see what it is.

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Friday, June 19th, 2009 AT 9:59 AM
Tiny
BUGIS55000
  • MEMBER
  • 1 POST
  • 1993 CHEVROLET TRUCK
  • V6
  • 4WD
  • AUTOMATIC
  • 185,000 MILES
When I turn my headlights on my brake lights don't work.
I checked all fuses.
I checked the brake switch under the dash.
Seems to work fine.
Again during the day when headlights are off, brake lights work.
Any advice?
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Saturday, November 21st, 2020 AT 5:13 PM (Merged)
Tiny
KENW1
  • MECHANIC
  • 213 POSTS
Thanks for visiting 2CarPros. This is a somewhat common problem on these trucks most often caused by a bad ground. Check continuity to ground with the tail lamp assembly unplugged on the black wire on each side. If there is no ground you'll need to either splice in a new one and connect it to the frame or look along the frame for the factory ground wire and repair as needed.

If both sides show ground the fault lies in the printed circuit boards of the tail lamp assemblies and they will need to be replaced. These were a high failure item on these vehicles. Below is the wiring diagram.
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Saturday, November 21st, 2020 AT 5:13 PM (Merged)
Tiny
JIMBO26
  • MEMBER
  • 1 POST
  • 1994 CHEVROLET TRUCK
I have a 1994 C1500 Chevy truck 135,000 that the brake lights will not come on when brake is pressed the tail lights come on when the lights are on but no brake lights I have turn signals and hazard lights Ive checked all of the fuses and cannot find any bad and have looked at wiring to tail lights again I did not see any thing wrong is there any other common problem that I have missed by some chance any help would be great thanks in advance.
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Saturday, November 21st, 2020 AT 5:13 PM (Merged)
Tiny
KIMBRU
  • MEMBER
  • 1 POST
I'm having a simular problem with my rear lights. The problem I'm having is when I put my turn signal on it cuts out the brake lights on that side. I have a 1994 Chevy Cheyenne. Have you found a solution to your problem. I've changed the bulbs, sprayed the electical fittings, cleaned them, changed the fuses and still same problem. Let me know if you have discovered something. Thanks
Kim
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Saturday, November 21st, 2020 AT 5:13 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Try adjusting the brake switch behind the pedal or replacing it.
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Saturday, November 21st, 2020 AT 5:13 PM (Merged)
Tiny
PHILIP-TX
  • MEMBER
  • 2 POSTS
  • 1993 CHEVROLET TRUCK
The brake lights don't work. I've checked bulbs, and wiring from bumper to fuse box. Replaced the switch on the pedal. Still no light! There is 12v at the harness connector that plugs into the switch, however. I removed the whole fuse PANEL. There is no (12v) power to the BACK of the "Brake" fuse. Not even the orange wire, while the bake is pushed. Is the any other fuse (in-line, etc) that I need to check? Couldn't find anything under the hood. Any idea where to look next? Thanks
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
PHILIP-TX
  • MEMBER
  • 2 POSTS
Found it. Fixed it.

If others have this problem.

It was the white wire on the end of the turn signal switch, that came loose/pulled out. One side had 12v on/off as the brake was pushed. The other side of the connector came out/disconnected.

Once again my son thinks his dad is a mechanical genius! :) (Got help from another forum)
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
  • 1992 CHEVROLET TRUCK
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 145,000 MILES
I have replaced brake switch and tested brake switch wires and when brake is applied the purple wire gets power. From what my repair manual says it should be the white wire but white wire seems like a ground if I use a test light between the 2 test light lights up. I have been trying to figure this out and can't seem to figure out what is going on here also on the brake switch the orange wire has ben disconnected and I am not sure where to connect it or if I need to.
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
CJ MEDEVAC
  • MECHANIC
  • 11,004 POSTS
I'm going with you may have a bad ground to the lights

the reason some of this may work (even dimly) is one wire is seeking any kinda ground thru it's neighbor wire.

I see this happen a lot with the lights on trailers

i had to screenshot the upper and lower halves of this diagram as "prodemand" would not let me copy it

looks like black is the ground (the right side of either diagram is the brake/ tail lights)

as a test, you might run a temporary jumper wire from ground, to the black wire to provide it with a "for sure" ground, till you can find the "open" on the original circuit. It may even look grounded, loosen the anchor and scooch it around or clean the area.

You should be able to see where diagram one overlaps diagram two

the medic
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,331 POSTS
Better find a spot for that orange wire because that's where the 12 volts comes from. That will show up on the white wire when the brake pedal is pressed. It's acting like a ground now because you're finding a path to ground through the signal switch and brake light bulbs.

The purple wire is part of the anti-lock brake circuit. That uses a different part of the brake light switch.
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
There are 3 flashers 2 near firewall and 1 behind fuse box. There is a 2 prong flasher behind fuse panel which controls blinkers, theres a 5 prong and a 3 prong flasher under dash near firewall. I am not sure what does what with those flashers or relays I would imagine the 5 prong does brakes etc mine lookalike 2 prongs are burnt probably from my having wires crossed at the rear of the truck

brown wire also get power when brake is pressed the brown wire is on the 2 wire connector on brake switch and goes towards firewall it seems like it goes behind relate panel

there is power coming in from 2 wires I think they were red. So I think I may have found the other part of the orange wire but when I hook it up to the brake switch it makes my passenger taillight stay on even when key is off and brake is not pushed so I don't know why that is but its the only orange wire I ave seen so far.
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 34,331 POSTS
The orange wire comes from the Brake light fuse in the fuse box.
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
Ok why would it make my passenger taillight stay on even when the truck key is not in ignition?
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
I am going to replace relays and flashers today and see what happens. My hazards stopped working but my turn signals and parking lights still work
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
I will let you know how I make out after replacing the relay and flashers see if brake lights work
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
STENNY
  • MEMBER
  • 13 POSTS
The orange wire kept brake lights on because I think spring in brake switch is messed up because it doesn't shut off taillights I tried adjusting it for like 20 min and no matter what I did brake lights stayed on when you let off the brake pedal, I would need to pull adjuster up to make brake lights shut off. Maybe I am adjusting it wrong idk anyone have some advice or can someone make a video of how to adjust brake switch that would help.
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Saturday, November 21st, 2020 AT 5:14 PM (Merged)
Tiny
KIRENE
  • MEMBER
  • 1 POST
  • 1989 CHEVROLET TRUCK
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 77,500 MILES
Brake lights have quit working. Changed fuses, and bulbs, and also replaced stop light switch. Still not working. Can you please help me? The turn lights and park lights are working.
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Saturday, November 21st, 2020 AT 5:15 PM (Merged)
Tiny
DARKESTNIGHTS
  • MEMBER
  • 10 POSTS
Pull your tail light covers and take the bulb plate off and buy new ones it will fix the problem it did the same thing to my truck and that fixed mine
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Saturday, November 21st, 2020 AT 5:15 PM (Merged)
Tiny
LOOMIS6
  • MEMBER
  • 1 POST
  • 1988 CHEVROLET TRUCK
  • V8
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
Brake lights work until I turn headlights on. Turn signals continue to work with headlights on, but no brake lights.
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Saturday, November 21st, 2020 AT 5:15 PM (Merged)

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