LED Tail light issues.

[AwesomeXJ]

I ran a search but didn't find what I was looking for. So Here's my question.

I installed 4in LED's into some rusty's taillight boxes. But they are acting really weird. Because i can't connect the turn and brake light on the same line. I had to wire my running lights/brake light to the top red LED and the turn alone to the bottom amber LED.

Here's the problem. when I have my running lights on and turn on a blinker it acts normal. But if the running lights aren't on and I turn a signal on it makes all 4 LED's (both left ones and both right ones) blink like a turn signal. Even if I unplug the turn signal LED and turn it on they all still light up except the one I unplugged. I thought it might be the grounds so I re-did them to all new ones. Still does it. If I turn on my signal (having all 4 lights blinking) and probe the parking/brake light wires with a light tester I read no power to any lines.

The only thing I can think of is that because they are LED's and not bulbs That the whole system is back feeding a volt or 2 making them light up, when a volt or two wouldn't light up a bulb. So I wasn't able to see the problem before.

Does anyone have any suggestions on exactly how I can remedy this problem?:hang:

 

[t-frady]

Ur right back feeding is ur prob sounds like to me
Search
But ill give u a hint use wires for the trailer lights
that should fix ya up!

 

[AwesomeXJ]

I tried searching. After 30 of 111 pages I gave up. I am using wires for my lights... Doesn't matter where I ground them it still does it. I'm thinking about running a small resister inline of the power wires so that it prevents anything lower than 12v from traveling through to the lights. Would this work?

 

[Reverend Jim]

A resisitor will drop your current going into the lights as well as backfeeding. Use a diode instead. It only allows current to flow in one direction and will not impead the flow going into your lights. But before you do that, double check your wiring. Most, if not all, LED lights have the diodes built into their circuit boards already to prevent exactly what is happening to you. Are you using replacement LED bulbs where the incandesents were? If so, the diodes will fix the problem. Good luck with your project.

 

[Shorty]

Most, if not all, LED lights have the diodes built into their circuit boards

I'd think all do (Light Emitting Diode)

 

[Reverend Jim]

I was wondering how long it would take for someone to catch that. Sorry O/P, I was bored at work. Hope you get your lights straightened out.

 

[AwesomeXJ]

I'm thinking a 12v relay would fix this problem

If I connect a relay inline to all the Lights wires that require a 12v source to engage the relay. anything less than 12v won't allow the relay switch to operate and thus won't continue to the lights. But when I press the brake peddle It will engage the relay and work properly. What do you think?

 

[Dozer11B]

Not sure if this will help, but did you upgrade the under-dash blinker relays?? I upgraded to the JCR boxes with LEDs and had to change out relays to EP27, I believe.

Still learning electrical myself (it still sounds like swahili to me), so if I am out of my lane, disregard!
:explosion

 

[AwesomeXJ]

Ya I put the upgraded relay in. It does this issue either way. I have a bunch of relays in my garage so I think i'll give it a shot when I get home from work.

 

[josefxj97]

when i did my lights last year, i didnt use any trailer wiring or anything fancy. I used a red oval LED for the stop/brake and an amber LED for the turn signals...its simple, just wire it straight to the LEDs. it sounds to me like you have a wire crossed somewhere.

 

[AwesomeXJ]

Thats what I did. If I disconnect my right blinker LED and turn it on the other 3 LED's blink. All of my lines have a current of aprox. 2.6amps running through them. thats enough to light up the LED's but not regular bulbs. We had a similar situation with and indicator light at work. when we put in an led it was lighting on 1volt but the bulb wouldn't. we just went back to a standard bulb and it didn't do it. I'm not putting in LEDs to save energy I'm doing it so I don't shatter housing on the trail anymore. and they look cool. If there is a crossed wire somewhere in the miles of wire so be it. I'm not interested in re-wiring my whole jeep to find it. I'm just curious if the relay idea would work or if this has happened to anyone else.

 

[MrKTroop]

Because i can't connect the turn and brake light on the same line. I had to wire my running lights/brake light to the top red LED and the turn alone to the bottom amber LED.

First off, unless I read it incorrectly, you have the brake light and the running light wires tied together to the top LED? That won't work. You would never see the brake lights come on if your running lights were on. You would need dual input LED lights like trailers have. This allows one input for the running light, and one for the brake light.

I would try to disconnect the running light wires from each side. Take the wires completely off, and see if the blinking problem is still there. If so, take the brake light wires off and put the running light wires on and see. If the problem is still there keep both running and brake light wires off and try again. Process of elimination will help you narrow down the problem.

Is it possible you have the running light (or brake light) wires backward on one side?

You said you upgraded the relay, so also check the front parking lights and make sure that they are dual filament lamps. If somebody put the wrong lamp in the front, it could cause a problem too.

Hope this helps a little or at least gives you another direction to look at. Good luck. It sounds like a 4 beer fix to me.

 

[AwesomeXJ]

Back of the LED takes a 3 plug connector (which I have). The wires are: white/ground, Black/tail, Red/stop & turn. And thats how I have them wired up. I cut the stock wires that ran to the OE bulbs and connected them to the LED harness. I went through the process of elimination for 2 days with no luck.

At this point the only options I see are to completely rewire the lighting system, ditch the LED's and go with bulb style 4in lights or get the SPST relay's to work.

 

[MrKTroop]

It just turned into a 6 beer fix.

 

[josefxj97]

i don't see those being your only options...
just a thought but maybe you didn't buy the proper LED's for what you are trying to do??
The red oval LED's on my jeep have 4 wires coming off them. its a STOP/TURN/BRAKE LED...i used a separate amber colored LED for the TURN and just capped off the corresponding wire from the red LED and the jeep that was supposed to be for the turn signals, this is how i was able to wire the jeep wiring straight to the LED's without any trailer wiring kit.
when the running lights are on and i hit the brake, the brake lights come on, when i use the turn signals, the amber colored LED begins to flash (and yes-i swapped out the relay). the only lights i don't have right now are backup lights....but i haven't needed them either

just my $.02....hope it works out for you

 

[AwesomeXJ]

I don't really want to have to buy new lights. I am doing the same thing as you basically. I have a red LED for taillight & stop light and an amber one for turns only. Everything I've done with all the wire tracing, and relocating grounds and checking and checking and checking.And still I don't see why or how this is happening other than because LED's run on current (amps) that a back feeding of (?)amps is causing the LED's to light. What ever is causing the problem it doesn't appear I can fix it at the tail end. And without diagnosing each lighting switch and fuse panel and everything the circuits go in and out of along the line. This could turn into a very time wasting and costly problem to resolve. So I am going to run with the relay idea, and if that should not work I'll sell my LED's and get 4in. standard bulb stop/tail/turn lights. Like I said earlier I did the conversion to run metal housing that don't shatter on the trail. So the lights themselves aren't quite as critical.

Thanks for all the info everyone. I'll post up my findings in a few days when I have time to try it.

 

[aintright]

i didn't read all of the posts in this thread, but did you try wiring in a tow ready 3 into 2 wiring harness for LEDs. i can get a part number for you if you want. or if it hasn't been posted already

 

[AwesomeXJ]

I don't know what that is. Can you post a part number? Thanks

 

[N8N_99xj]

This ought to be easy, but clearly it is not... I'm going to break this down real simply, and my apologies if I'm insulting your intelligence but sometimes it helps to start with basics.

You should have five wires going to each stock taillight assembly; brake, tail, turn, reverse, and ground.

Brake should go to the "bright" +12V connection on your red LED light.
Tail should go to the "dim" +12V connection on your red LED light.
Turn should go to the +12V connection on your amber LED light.
I dunno what you're doing for reverse lights, so I'm ignoring that for now.
Ground is obviously ground and common to all.

I'd unhook everything and retest the wires and/or compare colors to the wiring diagram and make sure you got it right. If you did, and you have a good ground (verify this - stuff can "sort of" work with a bad ground but you may get weirdness as you describe, although I would think the diode-ness of LEDs would prevent most of that) everything should work correctly.

I can think of one other possibility. Do you have a trailer hitch with a converter box for a trailer wiring harness? I've seen those converter boxes fail and cause all sorts of weirdness. If you have one, disconnect it and try again. If it now works, that's probably your problem. Oddly enough the last time I ran into this issue it was on a friend's Cherokee. Separate amber turn signals are a nice safety feature but those @#%#$%^ converter boxes can mess with you.

good luck...

 

[AwesomeXJ]

This ought to be easy, but clearly it is not... I'm going to break this down real simply, and my apologies if I'm insulting your intelligence but sometimes it helps to start with basics.

You should have five wires going to each stock taillight assembly; brake, tail, turn, reverse, and ground.

Brake should go to the "bright" +12V connection on your red LED light.
Tail should go to the "dim" +12V connection on your red LED light.
Turn should go to the +12V connection on your amber LED light.
I dunno what you're doing for reverse lights, so I'm ignoring that for now.
Ground is obviously ground and common to all.

I'd unhook everything and retest the wires and/or compare colors to the wiring diagram and make sure you got it right. If you did, and you have a good ground (verify this - stuff can "sort of" work with a bad ground but you may get weirdness as you describe, although I would think the diode-ness of LEDs would prevent most of that) everything should work correctly.

I can think of one other possibility. Do you have a trailer hitch with a converter box for a trailer wiring harness? I've seen those converter boxes fail and cause all sorts of weirdness. If you have one, disconnect it and try again. If it now works, that's probably your problem. Oddly enough the last time I ran into this issue it was on a friend's Cherokee. Separate amber turn signals are a nice safety feature but those @#%#$%^ converter boxes can mess with you.

good luck...

Thanks for the info. I'll look for a converter box. I do have a hitch with a 7 pin plug.