Why won't my turn signal and brake lights on the rear of the truck work

40

Asked by Apr 30, 2015 at 12:47 AM about the 1986 GMC Sierra

Question type: Maintenance & Repair

rear turn signals and brake lights don't work.  no power in yellow wire all the way to the firewall.  everything under dash works right, looks right, indicator lights work and front lights work fine.

9 Answers

81,465

Sounds like the turn signal switch in the steering column. Power for the brake lights flows through the turn signal switch to the rear of the truck. Since the indicators and front turn signals are working the fuse and flasher is good. Do the rears flash with the hazards on? HTH. -Jim

7 people found this helpful.
40

No they don't.

2 people found this helpful.
81,465

Check for power at the light sockets. Both wires are hot (+). One is for the tail lights and the other is for the brake and turn signal. The outer "shell" of the socket is ground. If you have no power there check for power at the turn signal switch. If you have power going to the turn signal switch but none coming out of the turn signal switch. The switch is bad. HTH. -Jim

1 people found this helpful.
40

Thank you so much! It was broken wires in the steering column. Purchased the new parts today, installed them and we have lights. Appreciate the help. My lighting diagrams never showed the wires for the brakes coming up thru the steering column so I never thought of looking there.

2 people found this helpful.
81,465

Awesome!! You're welcome, glad to help. Glad you found and fixed it! Thanks for letting us know. -Jim

2 people found this helpful.
100

I have a similar problem with my 85 Sierra. My front passenger side and rears don't work. Changed flasher brake switch still nothing. checked current through to rear . I'm getting power to socket but it doesn't blink when turn signals are on. bulbs have been checked and are good. Although when I turn the headlights on the signals cancels out and stays just stationary on the dash . Any suggestions would be appreciated.

8 people found this helpful.
50

The main brake/haz fuse under the hood for my 96 chevy 1500, pop's when i hit the brakes, also the right turn signal makes a sound and then pop's the brake fuses from inside the can. Can someone please help me out.

5 people found this helpful.

1972 Ford Pinto - Months back I installed red l.e.d in my (( back-up light sockets )) SO I"D Have really stand out brake lights IN THE REVERSE Sockets holes when I hit the brakes. I wired them into the orange right brake light wire. Last night I had my son do the lights while I watched from the back of car, then realized the right stock light and both back up lights would blink while the right blinker was on. When I turned the left signal on only single Stock light would blink. so I got back into it the wires trying to make ea LED in back up socket blink left to right within the system along with brake mode. Something is going on now. The left brake light wont come on or do blinker mode. Front left will blink. The right Brake/blinker light does it all. Both rear Running lights work. The green wire with red strip on left side gets no power all the way up to the front speaker kick panel. BUT, when I check for power at the brake light light switch, power is on one side of switch, then I press pedal down, power on other side. The Orange wire on right that works the brake/blink light has power and does it all as i said before. I've been at it for 3 1/2 hrs now trying to trouble shoot why the left rear blinker/brake gets no power. Going a little nuts, LOL HELP!!!!!

Months back I installed red l.e.d in my (( back-up light sockets )) SO I"D Have really stand out brake lights IN THE REVERSE Sockets holes when I hit the brakes. I wired them into the orange right brake light wire. Last night I had my son do the lights while I watched from the back of car, then realized the right stock light and both back up lights would blink while the right blinker was on. When I turned the left signal on only single Stock light would blink. so I got back into it the wires trying to make ea LED in back up socket blink left to right within the system along with brake mode. Something is going on now. The left brake light wont come on or do blinker mode. Front left will blink. The right Brake/blinker light does it all. Both rear Running lights work. The green wire with red strip on left side gets no power all the way up to the front speaker kick panel. BUT, when I check for power at the brake light light switch, power is on one side of switch, then I press pedal down, power on other side. The Orange wire on right that works the brake/blink light has power and does it all as i said before. I've been at it for 3 1/2 hrs now trying to trouble shoot why the left rear blinker/brake gets no power. Going a little nuts, LOL HELP!!!!!

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