Ongoing Electrical Problem

[Clay Perrine]

Hi.

 

I have an ongoing electrical problem. It started happening since shortly after the truck was purchased in 88. My father and I tried many times to find the issue, but no luck. When you turn on the headlights the turn signal indicators will (most of the time) come on and stay on. They blink with the signals, and nothing on the outside seems to be inop. This has driven me batty for 25 years. Anyone experienced this and can you offer suggestions?

 

Thanks,

 

Clay

[cruiser54]

This might be worth a try. Could help and can't hurt.

 

Improving the Instrument Panel Ground

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 knob. 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, Seatbelt and key warning, trans 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 have a 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 knob. You will see an 8mm stud there. Attach the large terminal end there with a washer and nut over it tightened securely.

**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.**

 

Revised 11-29-2011

[cruiser54]

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.

ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.

Revised 07/23/2012

[Clay Perrine]

Thanks.. I didn't know where the ground point was for the insturment cluster.

 

Ground issues are always a problem on old vehicles. I will add the wire you suggest and let you know.

[gogmorgo]

My dad's old chevy started doing that ths summer, but only with the left indicator light. We've been having issues with the indicator/wiper stalk, so i assumed that's what it was. Haven't done anything about it yet, but that's the first place I'd be looking. I'm pulling the steering wheel when I go home for Christmas to replace the key cylnder, so I figured I'd do the indicator switch/stalk while I'm at it.

[Eagle]

It's not the instrument panel ground. It's the front parking light sockets. They lose their ground and the parking light circuit backfeeds through the turn signal circuit to force a ground. Cleaning up the main ground point for the front lighting (located behind the driver's side headlight) may help, but usually it's as simple as replacing the two parking light sockets. There's a Ford socket that's usually in stock on the HELP! rack at the parts chains that fits perfectly.

[Clay Perrine]

It's not the instrument panel ground. It's the front parking light sockets. They lose their ground and the parking light circuit backfeeds through the turn signal circuit to force a ground. Cleaning up the main ground point for the front lighting (located behind the driver's side headlight) may help, but usually it's as simple as replacing the two parking light sockets. There's a Ford socket that's usually in stock on the HELP! rack at the parts chains that fits perfectly.

 

That is good info. I will check it out asap. (After I replace the worn out track bar on the front.....Death Wobble).

[danbyrambler]

My 87 MJ had a similar problem - - was a DS tail light socket - replaced all sockets + extra ground to frame - - - -There's no such thing as too much ground - - -

[cruiser54]

Here's a thought, too. In this write-up the connector for the lighting is described. Worth looking at.

 

I suggest unplugging EVERY electrical connection in the engine bay you can find, whether engine related or not, and spraying it out with a good electronics cleaner, visually inspecting the terminals making sure they haven’t retracted into the plastic holder, and then plugging it back together. There’s a critical 10-pin connector for the front lighting system located in front of the air cleaner and behind the left headlight assembly. Don’t miss that one. Also be sure that the connectors to the ballast resistor mounted near the air cleaner housing are clean and tight.

ALL of the relays should be removed, the terminals wire-brushed until shiny, and the receptacles sprayed out with contact cleaner. Then plug them back in. I do this on every Renix Jeep I purchase or work on for someone else.

Revised 07/23/2012

[Biotex]

I too suffer from this. Turn signals work fine until the parking lights are turned on. Since I knew about the melted headlight switch connector, I oredered a new switch and connector. In the mean time I thought I would just go ahead and check all the bulbs and sockets for grounds. I found the right front socket had a weak ground, so I replaced it. No change... I installed a new turn signal switch in the column, no change... I cleaned all the chasis grounds, no change...

 

I still think the problem is the headlight switch, but after reading this post, I will go back and add that 10" wire ground under the dash, and spray the 10-pin connector. and report back.

 

All the wiring in my truck is unmolested, and there are no signs of chaffing or anything out of the ordinary, so it sure seems like it could be a ground problem. Just can't figure out why the connector on the headlight switch melted in the past. heat buildup from a bad connection? At any rate, I WILL figure it out eventually.

[Biotex]

Update: Added grounds, no change...

 

So I pulled the headlight switch to test the connections per the FSM. The test for terminals B2 & I show that I should have ohms (continuity) between the two when the switch is in parking lights position and the switch is turned CW. I have no continuity between the two, so hopefully when my new switch gets here, it will fix it.

 

BTW, terminal I is the one that melted. Not sure yet what terminal I feeds, but will shortly. It is an orange wire.

[Eagle]

Just can't figure out why the connector on the headlight switch melted in the past. heat buildup from a bad connection? At any rate, I WILL figure it out eventually.

 

A bad ground causes resistance. Resistance causes heat. Basic physics.