Brake lights not working

[Ricky Olivares]

Good morning, new to this site. Pretty cool how square body community gets together to help out. Anyways. I bought a 1985 Blazer 4x4. I got the brake light fuse popping every time I connect brake light switch. Wire gets hot. I’ve changed turn signal switch at steering column. Traced wires to brake lights. And checked for grounded wires in back of fuse box. I also don’t have right turn signal light not working. Changed flasher. Then pops fuse for turn signals. When ignition is on. Dash lights go on. Without turning on lights. Lights work when headlight switch goes on. Also dash lights work. They put after market front amber lights in front with led lights. I’m thinking it’s those lights. Causing electrical problem. I hate electrical.

 

[Charlie]

 

[Snoots]

Possible short on the rear harness. I'd start looking from the back on both sides to the front.

 

[1973c10]

Welcome

 

[WFO]

Welcome from the Texas Panhandle.

 

[dvdswan]

Welcome to the site.

 

[75gmck25]

There is an electrical plug in the rear harness up under the back bumper near the frame, and its where you would plug in an adapter for a trailer wiring harness. If you disconnect that plug it should also disconnect the taillights from the system. That may be useful for troubleshooting/isolation. The harness also has a larger gauge white wire (12 gauge?) near there, which is used to ground the wiring harness in the back.

Bruce

 

[1987 GMC Jimmy]

Possible short on the rear harness. I'd start looking from the back on both sides to the front.

What he said. If you unplug the rear harness and it stops, that makes your job somewhat easier. If someone did work under there recently and a wire got pinched, that’s where it’ll be.

 

[Tank6x2]

Just as well to Check in behind the taillights as there’s a ground that sometimes has a poor connection to the body over time and a good time for a new set of bulbs

 

[Old77]

moved this to a more appropriate subforum