Jump to content

1987 Turn Signal Indicators


Recommended Posts

Hi all, I have a Renix 1987 4.0.

 

PO did some wiring and messed a lot of things up. I've just about got the wiring harness for the radio done, but had a 2 part question. (Waiting on the electrical manual).

Whenever i turn the headlights on, my turn signal indicators light up. Is this related to the cut blue tail lamp wire in the radio harness? 

Link to comment
Share on other sites

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, 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 knob. 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.

IP ground location

**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.**

Link to comment
Share on other sites

You may be using the correct terminology but, if so, the symptoms are confusing. Usually, the dashboard turn indicators lighting up is caused by a fault in the parking light sockets or ground, causing the parking lights to seek a ground by back-feeding through the turn signal circuit. That back-feed current is what's lighting the dash indicators. But the headlights don't share a socket with the turn signals, although they do share a ground, so the issue could still be a bad ground. What happens if you turn on the parking lights -- not the headlights, ONLY the parking lights?

 

Second test -- remove the headlight bulbs from the sockets and then turn on the headlights. Do the dash indicators light up?

 

On the rear lights, is it the taillights that are lit constantly, or is it the brake lights?

Link to comment
Share on other sites

29 minutes ago, Eagle said:

the symptoms are confusing

 

29 minutes ago, Eagle said:

On the rear lights, is it the taillights that are lit constantly, or is it the brake lights?

Add, are the license plate lamps ON?

Link to comment
Share on other sites

fixed the tailight issue- the brake power circuit wire in the column connector had frayed. I repaired the connection to the pin, and my brake lights work as normal. 
I've yet to see why the turn signal indicators are lighting up with the headlights. 
Thanks for the direction Eagle- I'll check the parking light circuits. 
I should have mentioned the PO swapped a XJ cluster in, and has really effed some wires. I've found multiple junctions under the hood for the ground using wire nuts.. 
Going tomorrow to the parts store for some wires and shrink wrap. Hopefully my electrical manual arrives this week.

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...