New member messed up taillights and needs advice

[ZenMonkey]

Good evening,

New guy here. Always wanted a jeep, specifically the YJ, so as the missus and I packed up to go our separate ways, me now needing my own vehicle after years of sharing, bought an 89 on a whim.

She was a weekend ride, and now my daily. Only 7 miles round trip, and the runs to the store, new place, etc. So of course she’s letting some issues that she sat on come to surface.

The most recent was the clutch master cylinder. Got that swapped, we good. But in the process, my big goofy gorilla hands were in a tight spot. So I carefully removed the main wiring harness blocking progress. Everything goes back together, clutch works better than before, but……..now my passenger taillight is very dull but the turn signal blink is bright as it should be, and the driver side rear turn signal won’t work with the lights on, works fine with them off.

I loosened and made sure the alignment of the wiring harness was good, the bulbs look okay…..but I’m lost. Prior to this, a buddy of a buddy wired in a harness for a trailer plug, but was unable to test day of. But when hooked up, the left turn signal had the trailer blinking hazards, right turn signal position was blinking the left trailer light, and regular and brake lights didn’t work at all. I’m going to blame it on whatever I messed up along the line. Kids a jeep tech at the dealership next county over, so I’ll start with my mistakes there and then work towards his work.

Am I changing fuses? Bulbs? Just buying a whole different vehicle because I’ve messed her up beyond repair? (Okay, that last one’s a bit of dramatic hyperbole).

Any and all advice is appreciated, attached is a picture of Betty’s first bath for reference of my current headache.

 

[Chris]

Good evening,

New guy here. Always wanted a jeep, specifically the YJ, so as the missus and I packed up to go our separate ways, me now needing my own vehicle after years of sharing, bought an 89 on a whim.

She was a weekend ride, and now my daily. Only 7 miles round trip, and the runs to the store, new place, etc. So of course she’s letting some issues that she sat on come to surface.

The most recent was the clutch master cylinder. Got that swapped, we good. But in the process, my big goofy gorilla hands were in a tight spot. So I carefully removed the main wiring harness blocking progress. Everything goes back together, clutch works better than before, but……..now my passenger taillight is very dull but the turn signal blink is bright as it should be, and the driver side rear turn signal won’t work with the lights on, works fine with them off.

I loosened and made sure the alignment of the wiring harness was good, the bulbs look okay…..but I’m lost. Prior to this, a buddy of a buddy wired in a harness for a trailer plug, but was unable to test day of. But when hooked up, the left turn signal had the trailer blinking hazards, right turn signal position was blinking the left trailer light, and regular and brake lights didn’t work at all. I’m going to blame it on whatever I messed up along the line. Kids a jeep tech at the dealership next county over, so I’ll start with my mistakes there and then work towards his work.

Am I changing fuses? Bulbs? Just buying a whole different vehicle because I’ve messed her up beyond repair? (Okay, that last one’s a bit of dramatic hyperbole).

Any and all advice is appreciated, attached is a picture of Betty’s first bath for reference of my current headache.

View attachment 124947

Welcome to the YJ club! Sounds like you're diving head-first into the joys of YJ ownership. Don’t worry too much about the issues; they’re pretty common and can usually be sorted out.

From your description, it sounds like a grounding issue or a wiring mix-up, especially considering the trailer plug modification. Here are a few steps you can take to troubleshoot:

Check the Ground Connection: Make sure that all the taillight grounds are clean and securely connected. Bad ground connections can cause all sorts of weird lighting issues.

Inspect the Wiring: Since you had to manipulate the main wiring harness, double-check that everything is properly seated and that there are no broken wires. Pay special attention to any exposed or frayed wires around the areas you worked on.

Test the Bulbs: Even if the bulbs look okay, it’s a good idea to test them in a working socket. Sometimes bulbs can be visually intact but still malfunction.

Fuses: Definitely check the fuses related to the rear lights. You might find a blown one that’s causing your issues.

Tail Light Harness: If the previous owner did some dodgy wiring for the trailer plug, ensure that it’s not interfering with your taillights. You might want to trace back from the taillight connections to ensure everything is standard and functional.

Don't worry too much about the drama of throwing in the towel. The YJ can be a bit finicky, but they’re incredibly rewarding once you get them sorted. Good luck, and keep us posted on your progress!

 

[ZenMonkey]

Welcome to the YJ club! Sounds like you're diving head-first into the joys of YJ ownership. Don’t worry too much about the issues; they’re pretty common and can usually be sorted out.

From your description, it sounds like a grounding issue or a wiring mix-up, especially considering the trailer plug modification. Here are a few steps you can take to troubleshoot:

Check the Ground Connection: Make sure that all the taillight grounds are clean and securely connected. Bad ground connections can cause all sorts of weird lighting issues.

Inspect the Wiring: Since you had to manipulate the main wiring harness, double-check that everything is properly seated and that there are no broken wires. Pay special attention to any exposed or frayed wires around the areas you worked on.

Test the Bulbs: Even if the bulbs look okay, it’s a good idea to test them in a working socket. Sometimes bulbs can be visually intact but still malfunction.

Fuses: Definitely check the fuses related to the rear lights. You might find a blown one that’s causing your issues.

Tail Light Harness: If the previous owner did some dodgy wiring for the trailer plug, ensure that it’s not interfering with your taillights. You might want to trace back from the taillight connections to ensure everything is standard and functional.

Don't worry too much about the drama of throwing in the towel. The YJ can be a bit finicky, but they’re incredibly rewarding once you get them sorted. Good luck, and keep us posted on your progress!

Thanks for the welcome! I knew I was gonna be finding issues, but dang, she should let me work thru my list before throwing out a bunch of new ones! I kid I kid. Though we did have a blown brake line the week before the clutch master went out, and I’m having an ongoing argument with my brake light switch since the day I brought her home. She wants the OEM bolt push pin, all I can find is a simple replacement that’s just not as good, and needs constant adjustment.

Definitely was wired wrong.
Passenger side was correct, driver side, instead of going in and wiring to the wires in the bundle, at the taillight, he wired both the turn signal and taillight wire into one small gray wire. Snipped them at the connector and wired right now. Didn’t fix the issue, have fuses and bulbs on hand to play with later, but a mechanic at the parts store said it’s probably that wire not liking the disruption. To either snip the end at the connector, and create a straight line again, and if that doesn’t work, follow the SOB and replace the whole thing.

So, added to my laundry list, right there with….replacing the power steering belt. changing out the fuel sending unit/possible a whole new fuel tank, figuring out how to get dash lights working, replacing the fuel filler hose, LED light upgrades, nonskid floor, upgrading from a body lift over to a suspension lift, the basics to start. Eventually deciding on the engine swap and finding a motor to rebuild and get the hands on with.

Looking forward to seeing what more experienced and capable cats have done, and learning along the way.