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jcgribks · 03-28-2011, 07:56 PM

1st of all I have a 2006 Wrangler Sport, auto and hard top.

I installed 4 Roadmaster diodes inline with the rear tail lights yesterday. I spliced into the wires where the harness runs below the drivers door sill. The brown w/red stripe went to the right stop/turn, the dark green w/red stripe went to the left stop/turn and I found 2 white w/yellow stripes that went to the tail lights. I wired these up per the instructions. But now after I have the diodes hooked up, the dash lights, shifter light, etc.. don't work. I've checked every fuse that I could think would have anything to do with lights expecially the one for the instrument lights. All are good. The little rotator switch on the turn signal arm will still turn on the dome lights but no instrument lights.

I checked the wires going to the diodes and of the 2 white w/yellow striped wires that both were hot when I turned on the lights and not when I turned the lights off, Now only 1 is hot. The other there is no power.
You can take the one that is hot coming from the dash and hook it to ether of the 2 that go to the rear and the tail lights work ether way.
I also hooked both the white wires back the way they were before I installed the diodes. They must loop back around from the rear because now my dash lights work. When unhooked, one is hot, one is not. But hook the hot one up and then the other loose one coming from the back of the wrangler is hot.

Now I'm lost as to how to wire in the diodes because since they loop back around to feed my dash lights, when I hook up my motorhome and turn it's lights on, the diode will prevent the power from feeding back into the one hot lead but if it just loops back anyway there's no way to stop it.

Any ideas?? Why does it just loop back around? Can I just connect both that come from the front and add in a wire to make a "Y". Then hook that Y up to the diode that way? If that's the case, then I only need 3 diodes and not 4.
Thanks, John

50 kw · 03-28-2011, 08:20 PM

I have a 2004 jeep. When I purchased it, it was pre-wired. When I plugged in my RV all kinds of lights quit. I found 2 or 3 fuses behind the glove box that were blown. I had to test each one with my meter to see if it was blown. The labels do not mean too much. Someone had removed the diodes and connected the wires together. Not at all good.

I cannot help you with the wiring as I have not started that yet.

legryz · 03-28-2011, 08:54 PM

I used the roadmaster diodes on my wife's 2010 Milan and so far everything is good (1 year)
Really can't help with the wiring problem but I do know the instructions state to mount the Diodes as close to the taillights as possible. Mine are mounted within 4 inches, that could be part of the problem.

jcgribks · 03-28-2011, 09:03 PM

50 Kw, I don't know what color wires your 04 will have for the tail lights. The 03 wiring diagram that I found on-line showed them to be black w/yellow stripes where mine are white w/yellow stripes. I couldn't get to the right side wiring as from underneath it's not open like the left side is. That's why I decided to hook up the diodes there below the drivers door sill as that's where all the rear wires run anyway. I just can't belive that Jeep ran the tail light hot lead (white w/yellow stripe) back to the rear lights and then ran it all the way back up front to power the dash lights.

But cut the 2 wires and only one has 12v and then the dash lights don't work. I even checked the 2 ends that go on to the rear with my multi-meter and they have continuity between them, so they are somewhere in the rear connected up to each other in a loop.

I think I can just hook the 2 white wires that come from the dash together along with another wire to form a "Y" and run that to the diode to the rear tail lights. I'll have the other one that goes to the rear just loose and not hooked up to anything but it will be hot so I'll need to tape it off.

I'm going to go to my local Jeep dealer and see if he can tell me why that wire jsut loops back to the front.

jcgribks · 03-30-2011, 06:56 AM

Problem solved. Jeep, instead of splitting off the tail lights from the front running lights and dash lights up front, they run the 12v hot line all the way back to the tail lights and then it runs all the way back up front to power the dash lights and the front running lights.

Now my Wrangler is a 06. I don't know how far back Jeep started running the wires this way. But when you find which color wire supplies 12v to the tail lights, my 06 was white w/yellow stripe, there will be 2 of them. I know by the 03 wire diagram I found, that year the color was black w/yellow stripe. Cut both wires and then you will find out that only one is 12v. Connect back up the two ends that come from the dash along with another wire to make a "Y". Attach this "Y" wire to one on the inputs to your diode. Now you still have the other two wired ends that are going back to the tail lights. It doesn't matter which one you use as ether one will work. If you hook up your multimeter to these two wires you will find that you have continuity between them so they are just a big loop. Hook up the output of the diode to one of these wires and just tape off the other.

Thats it. Now you don't have to fight tring to wire up the diodes up underneath back by the tail lights. Not counting the no space to even work on the right side. Also you only need 3 diodes instead of 4.

Another way to wire if up is if you want to have your front running lights on too and don't mind your dash lights coming on when you are hooked up to your motorhome, then after you cut the two wires, instead of making up a "Y", check and see which on is really the hot lead. Then hook that 12v hot lead up to the diode input. The other wire coming from the dash hook it back up to one of the wires going on back to the tail lights. The other wire going back to the tail lights you will hook up the to output on the diode.

This way you have the 12v lead coming from the light switch to run the tail lights, dash lights and running lights going through the diode. So now when you hook up your motorhome and turn on the motorhome lights, you will have all the running lights/tail lights work to instead of just the tail lights.