No Brake Lights?

Tiny
JBENCO83
  • MEMBER
  • 1999 GMC YUKON
  • V8
  • 4WD
  • AUTOMATIC
  • 170,000 MILES
I have no brakes lights at all, my lights work but when I step on the brakes I get nothing. I changed the switch on the pedal and checked the fuses what else good be the problem? There is no relay under the hood.

check both fuses under the dash and under the hood both good but still replaced the bulbs are good but still replaced, replaced the brake light switch and still no brake lights,

the tail lights, back up lights and directionals still work,
also no cruise control and that fuse is good.
Wednesday, May 19th, 2010 AT 8:53 PM

33 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Hey,

It could be the turn signal switch, but before you go testing the wiring and connections, try cycling the emergency flashers. What happens is the switch connection get corroded and stop working, when you move the switch it cleans the contacts.

If that doesn't work here are some wiring diagrams and guide to help you get the problem fixed.

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

and

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

Please run some tests and get back to us so we can continue helping you and check the blinker wiring diagrams so you can see how the system works.
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
+1
Wednesday, January 4th, 2017 AT 10:25 AM
Tiny
DON HOO
  • MEMBER
  • 1 POST
I had no brake lights at all, yet all other lights work as designed. Resolution to this was to find breakage in the wiring harness between the brake pedal switch and the circuit back to the brake lights. Due to repetitive bending the wire inside the insulation broke and another wore off insulation
Was this
answer
helpful?
Yes
No
+3
Monday, May 1st, 2017 AT 4:40 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 54,137 POSTS
Great addition to this thread! Please feel free to help out on the site whenever it can add information that will help.

Good find!

Cheers, Ken
Was this
answer
helpful?
Yes
No
Thursday, May 4th, 2017 AT 10:09 AM
Tiny
AEQUITAS14
  • MEMBER
  • 1 POST
  • 1999 GMC YUKON
  • 281,000 MILES
My brake lights went out on my truck. I checked the boards, bulbs, fuses, and replaced the brake light switch, and still no working brake lights. The running lights, hazards, and turn signals works.
My father ran a continuity test, and could not get power to the fuse box in the cab. I looked under the hood, and there is no stop lamp relay.
Is this a ground issue? If so, where is the ground located?
Any help is greatly appreciated!
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
The ground will be located on the lh side at rear of frame. Check to make sure all the pugs are connected at back of frame on lh side as well. If th eturn signals work then it may be the multifunction switch or maybe the trailer connector. Check the dark green and yellow wires from multi function switch while applying brake.
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
JOE DENALI
  • MEMBER
  • 13 POSTS
  • 1999 GMC YUKON
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 70,000 MILES
Also my taillights just have head lights. When headlight switch is off tail lights work. Put a new headlight switch, brakes switch is good, put all new bulbs.
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

The Daytime Running Lamps Module is probably bad in your vehicle. In the diagrams down below I have included a wiring diagram of the exterior lighting circuits for you vehicle as well as the headlights wiring diagram. As you can see the Daytime Running Lamps Module not only controls the headlights but has outputs to the tail/brake lights as well. I have also included instructions for the removal and installation of the DRL Module in the diagrams down below for you as well. Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros
Images (Click to make bigger)
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
+1
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
RUSTY PHILLIPS
  • MEMBER
  • 4 POSTS
  • 1999 GMC YUKON
  • V8
  • 4WD
  • AUTOMATIC
  • 230,000 MILES
My brake lights have stopped working. All other functions work, running lights, turn signals, just no brake lights. Therefore I am assuming there must be a switch under the dash that the brake pedal depresses that has gone bad. All advice is appreciated.
Was this
answer
helpful?
Yes
No
-1
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good evening,

Yes, there is a switch on the brake pedal under the dash. I attached the procedure and the picture for you to view.

Also, check the fuse listed in the diagrams I sent you for power on both sides.

Roy

1. Disconnect the negative battery cable.
2. Disable the SIR.
3. Remove the pushrod retainer from the brake pedal pin. Use snap ring pliers.
4. Unsnap the stoplamp switch from the pushrod.
5. Disconnect the electrical connector from the stoplamp switch.
Images (Click to make bigger)
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
RUSTY PHILLIPS
  • MEMBER
  • 4 POSTS
So long delay I know it wasn't the brake pedal switch. How do I check the fuse? And, can you think of additional possibilities? I did check to make sure the bulbs were good. ;)
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:29 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Did you verify power to the switch?

Roy
Was this
answer
helpful?
Yes
No
+1
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
RUSTY PHILLIPS
  • MEMBER
  • 4 POSTS
Nope by the time I figured out how to get the darn thing off I didn't consider that.
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Check for power to the switch.

Roy
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
JOE DENALI
  • MEMBER
  • 13 POSTS
  • 1999 GMC YUKON
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 70,000 MILES
White tail lights. When my headlights are on or taillights on just the roof light works. Changed bulbs sockets are good.
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
RUSTY PHILLIPS
  • MEMBER
  • 4 POSTS
Any help with how to do that would be appreciated.
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good afternoon,

Check for power to the stop light switch. I attached a diagram for you to view. Let us verify we have power through the switch.

Roy
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
+1
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Here is a guide for checking a fuse. You need a test light or voltmeter to test the brown wire to the switch.

https://www.2carpros.com/articles/how-a-car-fuse-works

Roy

Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
REDCANE1
  • MEMBER
  • 3 POSTS
  • 1999 GMC YUKON
  • V8
  • 4WD
  • AUTOMATIC
  • 112,000 MILES
My lights are new the fuses are good and I am getting power to the harness but the lights do not come on when the pedal is pushed down why
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,386 POSTS
First thing ill ask does the third high rise brake light work? if not chances are the brake switch is bad or misadjusted.

if the lights on then the turn signal switch has failed and you need a new one.

Read this guide on using a test light, it will help

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

The wiring diagrams for your brake lights are attached below
Images (Click to make bigger)
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Monday, July 27th, 2020 AT 10:30 AM (Merged)
Tiny
REDCANE1
  • MEMBER
  • 3 POSTS
None of the lights work and I have replace3d the brake light switch
Was this
answer
helpful?
Yes
No
+1
Monday, July 27th, 2020 AT 10:30 AM (Merged)

Please login or register to post a reply.

Related Brake Light Not Working Content