rear light goes out when lights are on

Sounds like you've got a bad ground at the light.

-- Old Crow '82 FLTC-P "Pearl" '95 Wrangler YJ TOMKAT, SENS, BS#133, MAMBM, SLOB#13, DH#2

Clear as mud...

So the brake light is on all the time? (you say the "brake light goes off")

What vehicle? As Old Crow said: most likely a bad ground.

Jim G While I have my lights on the rear light is on but when I apply my brakes with my lights on the rear light goes out. Do you know how I can fix the problem? It is a Jeep Grand Cherokee 2001

Are you looking for the wiring diagrams?

Yup, I'm defintly going with a bad ground here. I'd take the taillight assmebly out and look for a broken wire, first.

-- Old Crow '82 FLTC-P "Pearl" '95 Wrangler YJ TOMKAT, SENS, BS#133, MAMBM, SLOB#13, DH#2

The brake light ground is the fixture bolts.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Old Crow wrote:

On a 2001 Grand?

>

Your ground is the black wire in the bundle going to the lamp if it is the same as my '02 WJ.

Make yourself a jumper and touch it to a bare piece of metal and see if that gets your lights working.

If it does the ground is bad.

The official repair is to track the wiring harness backwards until you find where that wire is grounded and repair the ground.

Note: Accessing these pix required elementary school computer skills.

I can provide wiring diagram info.

They went all plastic didn't they.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

JimG wrote:

The lamp assembly housing is all plastic and the wiring harness includes its own ground. See pix

Note: Accessing these pix required special education school level computer use ability.

Some of the plastic ones still have a metal tab under one bolt, didn't know the GC was one of them.

Mike

Billy Ray wrote:

You've lost the ground on the offending lamp housing.

The brakes lights work fine, Bill. The trouble is that the lights are grounding through the brake circuit, and when the brakes are applied, the lights go off.

You have a bad ground on the left side light assembly. Remove the lamp housing and you should see the trouble. The lamp housing grounds through one of the screws that holds it on.

The actual repair is to take the lamp housing off and clean it up, then put it back on.

They are all trying to convince me that metal tab under the bolt no longer exists on the Grand Cherokee Jeff.....

Apparently the plastic housing now uses a wire for the brake light ground?

I don't know for sure because I haven't had a Grand apart.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Jeff Strickland wrote:

Cleaning the plastic is probably a good idea but I don't think it will correct a bad ground in this case as there is no metal to metal contact except through the wiring harness.