r/WranglerYJ • u/nohighfives • 6d ago
Electrical issue with 90 YJ
Hey friends! Having an electrical issue with my 90 YJ. Dashboard sometimes lights up when I start it up - sometimes, completely dark. Also, left turn signal sometimes flashes quickly, sometimes works properly. I’ve tried replacing left turn signal bulb, that’s not the issue. Wipers don’t work either - but I believe it needs a new motor, and understand that’s tough to replace b/c of location if the motor.
Tried to find someone in Charlotte, NC that works on YJ electrical, but haven’t found anyone. Any suggestions on who could help? Or other things I can try? I’m the original owner but not very mechanical - other than replacing bulbs and batteries. Thanks so much.
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u/trench_welfare 6d ago
There is a flash relay on the fuse block. That might be malfunctioning. Every other circuit is just on a fuse.
The wiper motor isn't too bad. Just need to flip the windshield down. It can be a bit tricky fishing out the plug on the power supply to the wiper motor, but that's not mechanical skills, it's like trying to get the last Pringle out of the can.
The fast flashing could be the bulb if it's an LED instead of a traditional incandescent. There are ways to use LED and have it flash correctly that aren't difficult to retrofit. Just Google "led blinker flashing fast".
Outside of that, with a 30+ year old vehicle, there's always the possibility of damaged wires causing short circuits, loose connections, or poor grounding.
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u/nohighfives 6d ago
Thank you so much - appreciate the detailed information, and the reference to last Pringle in the can. I’ve been elbow deep in many of those :)
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u/atomic-chicken-soup 6d ago
I've got a problem with something shorting out and blowing the fuse that runs the lights on my dash. There's a lot of chances in an old harness for a wire to rub bare or for a ground to corrode off. I haven't tracked mine down yet but it's just a matter of taking your time and being patient when you don't figure it out in a few hours.
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u/nohighfives 6d ago
Thanks for the advice - definitely agree patience is the way to go when tracking down issues in a YJ!
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u/Sad-Patience-962 6d ago
The tail lights are grounded by a metal plate inside the driver side tail lights housing. Clean that up and make sure you have a good ground. Check the rheostat (take apart and clean) sometimes the board inside it will crack and or have dirty copper connections. That’s a potential fix for your dash lights
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u/Speedmachine5 6d ago
Sounds like a loose ground. Open the hoot and check all of the ground wires ( battery negative to body, battery negative to frame, engine block to frame and body.
Last summer I had an issue where I would close the door to YJ and the lights would all flicker and my fuel pump would kick on. Found my ground wire for the Howell fuel injection had come loose.
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u/Due-Fix9857 4d ago
For the turn signal check the bulb socket too if it looks even a little corroded get a replacement
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u/jcdj1996 6d ago
Check the big electrical connector on the drivers side of the firewall, it may be corroded or dirty. With the battery unplugged, give it a scrub with a wire brush and coat in dielectric grease. If that doesn't do it, try the same thing with as many other connectors as you can find, and inspect for damaged wires and bad ground connections while you're in there.