Brake/tail light issue

[snoz]

Hello all,

I'm new to the forum and trying to help a friend with his 2002 Mountaineer. I hope this is the correct place for Mountaineer questions.

My friend recently purchased this vehicle and it has no tail lights or brake lights. The turn signals do work though. It turns out that fuse 23 blows every time the brake is applied.

Here's what I've done so far. I replaced the fuse, hit the brake, it blows immediately. I disconnected a tap off the wire to the brake switch for an aftermarket alarm/remote start, hit the brake, same result. I then disconnected the wiring harness from the sockets on each rear light (including 3rd brake light) and retried with the same result. I looked at the trailer wiring and it appears to be unmolested and just plugs into the harness under the passenger tail light.

Do you have any thoughts on what I should look at next? Thanks in advance for any advice you may have.

Thanks,

-Ethan

 

[Number4]

Sounds like the circuit is grounded somewhere. Perhaps this is obvious. If the bulbs aren't popping, then I'd think the ground is closer to the fuse box. Could even be within the brake switch.

Just my theory.

 

[snoranger]

Along with the wiring, Don't forget to check the shift interlock (the solenoid that stops you from taking the shifter out of park without applying the brake), that could cause the stop lamp fuse to blow.