1988 GMC C1500 Brake lights

1988 GMC C1500
109,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
DSISTRUNK
  • MEMBER
  • 2 POSTS
I have replaced the brake light switch on my daughters 88 GMC pickup and still have the same problem. The brake lights do nothing when you step on the brake pedal, however when you turn on the parking or the headlights the brake lights light up perfectly along with the tail lights. All hazards/signals work fine and the bulbs and fuses are all good. Could this be the headlights switch? Or do you have any other ideas?
Oct 8, 2008 at 12:39 PM
Avatar
JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,248 POSTS
Hi:
With the lights off, are you getting power to the switch?
Dec 15, 2008 at 9:00 AM
Avatar
DSISTRUNK
  • MEMBER
  • 2 POSTS
Hi, yes it is getting power to the switch with the lights off. I have since replaced the headlight switch and still have the same problem.
Dec 15, 2008 at 9:21 AM
Avatar
JACOBANDNICKOLAS
  • ✓Experienced Mechanic
  • 110,248 POSTS
Hi:
I need you to check the tail light sockets of damage. If they are ok, check the socket for power when the brake is applied. Make sure the test light has a good ground. At this point, something is telling me that there is a ground problem. When you have the lights on, the brake lights are grounding through the switch. Also, at the brake switch, have you checked for power out with the lights off?

Joe
Dec 15, 2008 at 9:47 AM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle