electric windows and door locks quit working, figure it is a blown fuse but haven't checked yet. Just found that tail and brake lights work until you turn on headlights. Headlights on, no brake or tail lights, headlights off tail and brake lights work as they should. Sounds like a bad ground somewhere but don't know.
Hopefully someone has an idea that will help me. This is on a 2000 grand cherokee.
Thanks.

 

I'm not a grand Cherokee guy but there very similar to my xj.

you have to start at the door jams where the wires pass through into the cab that's where i found 1 of my 2 issues a broken wire there and a wire grounding out on the passenger side right before it connects to the fuse box that fixed my passenger side locks and my windows going up and down. if I remember correctly if the pas side switches are no good the back ones will not work either. also check the wires to the fuse block/relay under the hood.(it doesn't hurt)

i dont necessarily think the light situation is connected, but you never know and jeeps are known for bad light switches (i bought a 2001 xj with light issues to find out there were melted wires at the switch and everything was wonky 1 head light no tail lights brakes worked gauges were screwy etc and for some incredible reason there was a wire cut and a fuse ran up into the cluster smh).

let me know how you make out. the obv is always the fuses and relays but you know that already. Good luck

 

I'd try measuring the output of the switch panels to determine if any of the switches are bad, and then see if you're getting any power to the power window regulators and door lock actuators. You could have a kinked wire in the door jamb wiring boot that would need to be addressed, or it could even be a faulty BCM (Body Control Module). Again, the simplest thing to do is to take a multimeter, and measure the output of the switches and power window regulators/door lock actuators to see if any aren't getting power, then replace them as needed.

-Vince