I just finished replacing the ac evaporator and heater core in my new to me 97 XJ 4.0I6. after reassembling everything I have the weirdest electrical problem. None of the following works:

dash illumination
gauges
parking lights (front and rear)
side marker lights
turn signals
brake lights
backup lights
ac compressor (even when jumping the low pressure switch)
hazard flashers
Parking brake indicator lamp

When metering the voltage on the 12v accessory outlet the reading is 6.3v with the glove box door open, but when closed I read 12.3v. The 4wd and shifter lamps glow dimly with the glove box door open and extinguish when the glove compartment door is closed.

Has anyone had a similar problem? I am at wits end trying to locate the failure point. I have disconnected and cleaned (contact cleaner) all of the brick type plugs under the dash and all fuses check OK. What have I done wrong? Please help!

 

Almost sounds like your main chassis ground is bad. Try running a jumper from battery - to the chassis and see what happens.

 

I agree that it is likely a ground issue.

 

I will try the ground jumper idea this morning and reinspect the cabling for any pinched or nicked wires. Thanks for the input fellas. I will post the results as soon as I have finished.

 

Just got finished....again. Installed a jumper from battery neg. to inside of fender under a fender screw. Disconnected all connectors to the dash, swung the dash out, inspected all wiring, found nothing suspect. Reconnected all connectors ensuring that they are well seated, hung the dash on the two studs below the windshield, reconnected the neg. battery cable, turned the ign. sw. to run and lo and behold the gauges came up! No turn sigs. or flashers unless you hold the button on the glove box in. Hold it in and turn sigs and flasher works. Turn on the headlights and all gauges go to 0, both turn sig. arrows light up and the airbag light comes on. Turn off the headlights all goes back to normal. What do I check now? Headlight switch maybe? Everything worked great before I took the dash out. The rest of the project was easy except for this electrical garbage!!! Help!!!

 

Replaced the headlight switch today and tightend the nuts on the ground points behind the dash on the passenger side and now everything works! Thanks for the help and opinions.