Exterior LED Upgrade Problem

I recently decided to upgrade my exterior lights with LED as many of us have done. I have a 2000 XJ and went with LED bulbs from superbrightleds.com for the front. The rears are also from the same site, however I am using JCR's tail light boxes and therefore I had to use trailer style lights for the rear (oval tail/brake light, one 2" round red, and one 2.5" round amber for each side). I also put an LED bulb in the third brake light. The problem Im having is that after installing the front LED bulbs and working on the wiring for the rear, I cant seem to get things to work right. The hazards are acting up, whereas the third brake light and even fog lights will flash. The turn signals are acting strange also, one of the signals indicators on the dash will remain solid on, the brake lights dont work, and everything is just generally FUBAR. I bench tested all the bulbs/lights and replaced the factory flasher relay with an electronic one from AutoZone which says LED on it (meaning its designed to work without a standard load). Im kinda puzzled; and because things arnt working as they are meant, I cant properly wire my tail lights in. Has anyone dealt with this or have any ideas what I may have missed? Thanks.

Start up your google-fu. If I remember correctly there is an issue with the amperage difference between standard and LED lights. This difference will cause all kinds of wonky light issues. I beleive an aftermarket flasher is needed for both the turns and the hazzards. Those that have done it could chime in, but with a little digging, you will find that you are not the first.

Sounds like you are having a couple of things happening at the same time. You will need the LED turn signal flasher. It's about $12 to $15 at Vatozone IIRC. It should be one combo flasher. After that check your wiring for the aftermarket brake lights. You might have things crossed there.

Danger Dave said:

Sounds like you are having a couple of things happening at the same time. You will need the LED turn signal flasher. It's about $12 to $15 at Vatozone IIRC. It should be one combo flasher. After that check your wiring for the aftermarket brake lights. You might have things crossed there.

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Dave, I got the LED flasher (the one under the dash to the left of the steering column) and installed it. I tried every combination with the three wires from the tail/brake light to the three wires on the LED light and it just doesnt seem to work right. The turn signal (seperate light) does seem to work however. Could there be a different relay?

You can't just wire up the LEDs to the normal bulb plugs. You need a trailer light wiring harness to allow you to use the stop/turn/tail lights in place of separate turns.

Check this out, worked for me. I used two harnesses, one for each side, to simplify the wiring.

http://www.naxja.org/forum/showthread.php?t=980571&highlight=stop+turn+Tail

Maybe Try

xjwisconsin said:

Start up your google-fu. If I remember correctly there is an issue with the amperage difference between standard and LED lights. This difference will cause all kinds of wonky light issues. I beleive an aftermarket flasher is needed for both the turns and the hazzards. Those that have done it could chime in, but with a little digging, you will find that you are not the first.

Click to expand...

Yes the loading issue on the circuit is important. I've converted numerous vehicles to LED and that LED flasher alone won't always do the trick. Due to the way the circuit is wired, you may need separate loading resistors on each side (can hide behind the taillights).

One test you can do is connect one of your old signal lamps to the circuit and see how it flashes. If you flash normally again you have a loading problem in the circuit - super flashy is not enough load and stuck on is too much usually.

Finally, the Haynes or Chilton.... Hmm think it's the Chilton manual, has some decent wiring diagrams I think - you could re-identify your oem harness wiring to make sure you didn't mix something up there.

I'd like to suggest you revert to what worked if possible, just let it all hang there and make one change at a time testing each alteration. The XJ taillight is one of the "busiest" I've ever seen with 4 lamps in it - 2 duals the engineer really went to town on that one. :looney:

Re: Maybe Try

X E Ryder said:

Yes the loading issue on the circuit is important. I've converted numerous vehicles to LED and that LED flasher alone won't always do the trick. Due to the way the circuit is wired, you may need separate loading resistors on each side (can hide behind the taillights).

One test you can do is connect one of your old signal lamps to the circuit and see how it flashes. If you flash normally again you have a loading problem in the circuit - super flashy is not enough load and stuck on is too much usually.

Finally, the Haynes or Chilton.... Hmm think it's the Chilton manual, has some decent wiring diagrams I think - you could re-identify your oem harness wiring to make sure you didn't mix something up there.

I'd like to suggest you revert to what worked if possible, just let it all hang there and make one change at a time testing each alteration. The XJ taillight is one of the "busiest" I've ever seen with 4 lamps in it - 2 duals the engineer really went to town on that one. :looney:

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I appreciate the suggestions, I was however hoping not to use resistors in an effort to reduce the load on the 12V system, and also not have to worry about long term exterior light use with the engine off (as this is an expedition build and I will be concerned with conserving battery power and fuel). If I am mistaken let me know, but I thought this mod was possible to do with out the resistors.

Also, the trailer converter box idea (in the linked write-up a few replies back) seems like and unnecessary step, unless Im missing something here. The wires are all labeled and color coded on the tail lights, and worse case scenario, I can use a test light or volt meter.

Keep the info/ideas coming. You guys are better than a Haynes manual :clap:

Re: Maybe Try

Ice_Man said:

If I am mistaken let me know, but I thought this mod was possible to do with out the resistors. QUOTE]


Yeah, I did too. Thats why I got the LED bulbs with built in resistors. Mine don't seem to be working completely though. Also depends on how the bulb is inserted into to the socket. One way it might work partially, flip it around and plug it in and it wont light at all

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Re: Maybe Try

Ice_Man said:

I appreciate the suggestions, I was however hoping not to use resistors in an effort to reduce the load on the 12V system, and also not have to worry about long term exterior light use with the engine off (as this is an expedition build and I will be concerned with conserving battery power and fuel). If I am mistaken let me know, but I thought this mod was possible to do with out the resistors.

Also, the trailer converter box idea (in the linked write-up a few replies back) seems like and unnecessary step, unless Im missing something here. The wires are all labeled and color coded on the tail lights, and worse case scenario, I can use a test light or volt meter.

Keep the info/ideas coming. You guys are better than a Haynes manual :clap:

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You really should be ok to replace any of the lights except turn signals without an issue. The front park/turn can be tricky and as another member has posted, you can work around it with some Bosch relays.

Re: Maybe Try

X E Ryder said:

You really should be ok to replace any of the lights except turn signals without an issue. The front park/turn can be tricky and as another member has posted, you can work around it with some Bosch relays.

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My plan is to undo everything and bring it back to stock (with the exception of the drivers side rear which I have cut the wires to start to wire up the truck lights). I will then start in that location and do one at a time, testing and whatnot. Do you think you could elaborate a little more on the Bosch relays on the front park/turn? Thanks.

hubs97xj said:

http://www.naxja.org/forum/showthread.php?t=1090569

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:thumbup: That helps, thank you. Hopefully I can get it all to work. I think Im going to try and take some pictures and do a write-up after all of this.

Ice_Man said:

:thumbup: That helps, thank you. Hopefully I can get it all to work. I think Im going to try and take some pictures and do a write-up after all of this.

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Good looks like hubs got the linkage for ya - carry on! :clap:

X E Ryder said:

Good looks like hubs got the linkage for ya - carry on! :clap:

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Yeah, gonna work on it this week and Ill post updates and maybe some pics if I finish.

BTW: Just got done reading your build thread and Im digging the rig. Im doing something very similar with mine (a 2000 XJ). Im sure Ill put up a build thread when I make a little more progress (got most of the parts, just need time to work on it). Keep up the good work.