Hi there
95 XJ with some electrical problems that have reared their ugly heads recently. Two issues occurred within a few weeks of each other so they might or might not be related.

Issue #1: Dome lights on all the time/other circuits possibly drawing power. Have checked door plunger switches. Replaced the rear cargo light assembly as the button became stuck when I tried to make sure the rear light was switched off. Switched to LED overhead lights and now it takes several days to drain the battery, which tells me not a lot of power is being drawn. Pulled every interior fuse that made sense and lights remained on.

Issue #2: Instrument cluster, radio, shift light flickering and going nuts under more than 30% throttle. When cruising things seem normal, but when you apply throttle to accelerate all of the gauges would go haywire and read anywhere from 0-max. Replaced alternator but speedometer is still jumping around under acceleration.

I'm looking for help on narrowing down where this short is. Inspected the instrument cluster connections and circuits and did not find anything with a cursory check. Cleaned all contacts for alternator (before eventually replacing the alternator). Cleaned contact area and put new terminal ends on oil dipstick ground. Checked for possible short on wire harness under interior panel in rear driver side door based on a post I found, but found nothing. Have access to a multimeter.

Thanks for any and all help.

 

Any wiring being touched by the gas pedal up under the dash?

The ground behind the spare tire?

Is there a cobbled up trailer harness?

 

The Dash Harness grounds to the metal framework of the Dash right underneath the Steering Wheel. The metal framework then grounds through its mounting bolts, which is not good. In addition to checking that ground wire, it often times does wonders to a XJ to add a short length of wire running from the metal structure of the dash down to a bare metal spot on the kick panel.

 

CRUISER'S MOSTLY RENIX TIPS

IMPROVING THE INSTRUMENT PANEL GROUND

NOVEMBER 17, 2015 SALAD 27 COMMENTS

The ground point for the complete instrument cluster on your XJ or MJ is located up under the driver’s side dash. If you lay on your back and look up under there with a flashlight, without wearing a hat, you will see a black wire attached to a shiny piece of metal almost directly above the hood release ****. The screw will have either a ¼” or 5/16″ head on it.

This ground point is responsible for handling the ground circuit for the following items: Dome lamps, seat belt and key warnings, transmission power/comfort switch, wiper switch, headlamp switch and delay module, fog lamp switch, cargo lamp switch, all instrument panel grounds and illumination, power windows and door locks, cruise control dump valve, and a few more things.

The problem is that where the ground point is located does not share good contact with the chassis where the ground should be. The solution is simple:

• Make up a jumper wire with #10 gauge wire about 10″ long. On one end, crimp on a ¼” round wire terminal. On the other end, crimp on a 3/8″ round wire terminal.
• Remove the screw from the existing ground wire and attach the small terminal of your jumper so that the original wire and your new jumper share the same attaching point, one over the other.
• Look above the driver’s side plastic kick panel just forward of the top of the hood release ****. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely. Use a coating of OxGard at all ground contact surfaces when attaching the screw and nut.

**Special note for Comanche owners: Make your jumper wire 12″ long and attach it on the driver’s side kick panel close to the fusebox on the 8mm stud.**

 

Thanks for the suggestions. I will try each of them and report back with any progress. I forgot to mention in my first post that the dome light/parasitic drain (even without the bulbs in) issue started about 2-3 weeks before the instrument cluster/radio/gauges/etc. flickering with acceleration.

 

To assist diagnosis, connect test light between batt and terminal, it will glow due to parasitic draw

commencing in the engine bay, pull each fuse one at a time and see if it goes out. Always just pull one, then put it straight back in

if not, using a light and mirror, do the same for the under dash fuses

if it still does not go out (or do this first), make a temp ground for dash and see if it goes out

next up, I would start pulling "suspect" harness connectors..what you are looking for is the test light to go out.

At this stage you will be needing to closely study the FSM, descriptor, circuit diagrams, harness connector locations etc etc

Electrical fault finding must be undertaken in a systematic manner, any thing up to this point requires almost zero electrical knowledge, only a couple of hours,
very high chance you will locate the issue, if not, you will have narrowed it down very much, and should ask for further advices