Brake Lights

[likearock78]

1988 GMC truck brake light problem. Turn the lights on and the tail lights come on but no brake lights when I push the brakes. But if the lights are off and I hit the brake they light up. Any suggestions?

[bill190]

Check to see that you have the correct bulbs installed.

[likearock78]

they should be. they used to work fine untill a little while ago

[bill190]

You could try activating your hazard light switch a couple of times. On/off.

 

Then try removing the bulbs in the rear and reinstalling them. Might try cleaning the sockets with a paper towel.

 

Then disconnect/reconnect the wiring harness connection under the rear of the vehicle. If trailer lights tapped in, examine that wiring closely.

 

Other than the above, you will need a wiring diagram and a multimeter to test and find the problem.