Headlights and turn signals/parking lights malfunctioning

[tizzdizz]

On my way home from work, my turn signals suddenly stopped working. At first I thought it was a bad bulb, but both sides are flashing fast, and my headlights are also not working. When I turn on any of these lights, the high beam indicator and both green arrows light up, and my odometer flashes bright/dim.

I checked all fuses, and they seem good. When I turn on the hazards, they start flashing erratically, then I hear a buzz sound and they flash less and less. I'm not really sure where to look to find the problem, and I'm worthless with finding electrical/grounding issues. Does anyone have any advice or previous experience for me?

The one thing I can't STAND is electrical issues.

One thing I'm relatively sure about is that it's limited to the headlight harness, but I don't know how to test that theory. A buddy helped me determine that this harness has +12V to the plug behind the core support whether it's malfunctioning or not.

Is there somewhere I can pick up a stock replacement harness if needed? I'd like to just plug-and-play if possible. I know people upgrade their wiring, but I just want the damn thing working first. Thanks for any advice you guys might have. I posted this on other forums, but I have a feeling there's a higher concentration of more knowledgeable people here.

 

[Arkansas91XJ]

It sounds like you have a 97+ XJ. Have you tried the cluster calibration/self test yet? With the key in the off position, hold the trip reset down and keep holdin as you turn the key to the on position. Your gauge cluster should do some funky stuff and flash some lights. It should help eleminate it as a possible cause. This is based off my 01 XJ and the FSM for it anyway, but I would assume this would work on any 97+ as I believe the clusters are the same p/n

 

[Arkansas91XJ]

Just skimming thru my FSM on the gauge cluster here. It looks like your hard wired stuff is screwy. Does your liftgate ajar light work good? With the ignition on, does your MIL come on at all? If it's giving you fits all around, I'd pull the cluster out and clean the connectors, otherwise the FSM says bad cluster

If everything else seems to work, then you could really easily go to a junkyard and yank a front end harness and see if it makes anything better.

 

[tizzdizz]

Hmm, that's a thought. I had considered it being the headlight switch, but if it were a bad cluster, would that affect the external lighting too? Never heard of that test either. I should have included my vehicle information, oops. It's a 99 sport with a 4.0 AW4. Thanks for the tips, I'll dig deeper tonight and see what I can find.

 

[Arkansas91XJ]

After I slept it hit me like a bag of bricks, it seems soo obvious that it's your front end harness doesn't it. I thought maybe the headlight switch too, but it is affecting your turn signals as well. It would be real easy to go to a junk yard and grab a harness and plug it in for a quick check to see if it solves the problem. If it doesn't, it's a near safe bet that the failure is before the front light harness connects to the main harness.

As for your hazards flashing erratically and your blinkers blinking fast, is this based off the green lights in your cluster, or inspection of all lights? Later XJ's have that nifty thing where when you turn the hazards on only one side blinks on the cluster, but they blink all around externally.

 

[tizzdizz]

FOUND IT. It was a dirty/loose ground screw on the driver side fender. I was suspect of the ground before, but my mechanic friend came over with some wiring diagrams and a sharp mind and helped me track down the real issue. Always start here if you ever have headlight issues! It was right in front of us, but we were looking for bad wires for a while before it dawned on us.

these buggers:

Also put in some Silverstars. Much better! Here's how they compare with stock wiring.

Thanks for the tips Arkansas!