I have a 1996 Blazer, 4 door, 4x4, 4.3L. Brake lights, hazard lights, and both turn signals stopped working (no relays for turn and hazard lightsclicking either). All other lights work. I am thinking that the brake, signal, and hazard lights share a common ground. I recently wired in a plug for trailer lights, but I don't think that is the problem, since it was just a simple wiring splice into existing trailer wiring provisions. There is no continuity for the trailer plug ground, which leads me to believe it's a grounding issue. If this indeed the case, where would I find the common ground? Any help is greatly appreciated.

Martin

 

I'd check the flasher relay first just to be sure that it isn't something simple..

 

If the flasher relay doesn't pan out... Try grounding the ground wire to the chassis and see if they start working again, then you'll know for sure if it's a ground issue...

Did you check the fuses?

 

Fuses are all good. This model has seperate turn and hazard relays, so they're either both good or both blown. Still dosen't explain the brake lights not working if the relays are blown. Traced the wiring from the trailer plug to the engine bay. The wiring checks out in the back end, so I think the problem is between the plug in the engine bay and the dash.

 

Try plugging your trailer in, and seeing if the lights work, if they do... it's a problem with the splice job...

I'm not sure what would cause brakes/signals/hazards/tails to fail all at once, lol

 

Are brakes, signal and hazards all routed through one of the hazard/signal relays maybe?

 

I should add that at the trailer plug, the three brake/turn wires all have continuity to ground, but the one ground wire does not have continuity to ground. When disconnecting the wiring harness plug in the engine bay, the 3 trailer wires that had ground, no longer do. Which leads me to believe it's something up front, not in the rear.

 

Tails still work. It's the hazard/turn/brakes that don't.

 

If it's a ground issue, then either fix the harness, or reground the wires...

 

Success! It was the fuse all along! I guess when I pulled out the fuses to begin with, the little fuse removal tool was blocking the broken part of the fuse element, which had just a hairline break in it. After getting frustrated, I decided to pull out the fuses and do a continuity check on them. That's when I spotted the tiniest break in the fuse.

For future reference, it was the #1 fuse labeled "Stop" (for a1996 Blazer, 4 door, 4x4, 4.3L, auto xmsn).I guess if that fuse goes, your turn signals and hazard lights also don't work.

Thanks to the guys who provided input.