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jetskier111 09-10-2012 03:13 PM

Trailer wiring gremlins...
Hey all,

I have a 2004 TJ but figured I would post this here to get more opinions.

I hooked up the trailer I have (new wiring on it with no issues) to my TJ. It had a wiring harness already but it looked old.

BEFORE I hooked it up, all electric items worked fine.

After hooking it up we had gremilns appear

what its doing now:
-when I hit the brake pedal the lights (in and out) turn on (funny but annoying)
-the right turn signal turns on a form of the hazards (right signal is brighter then the left but both flash)
-when headlights are on the right signal doesn't work
-left signal is fine.

I guess that hooking up the trailer, ie using the sketch harness, made some sort of short. The ground looks good.

I was thinking about just pulling the whole harness that is spliced in but figured I would ask for some advice before hand...


ballistx 09-10-2012 07:03 PM

check the ground
Typically, when I have had weird gremlins in the trailer lights it has been the ground.

When it is hooked up, take a set of battery jumper cables and connect both to ground on the vehicle and the other end to the metal on the trailer. See if the lights work properly then.

harleydragon 09-11-2012 07:48 AM

if that does not work and you know for sure that the trailer wiring is good then wire in a new pigtail on the jeep that you know is correct and yes make sure you have a good ground

ballistx 09-11-2012 08:29 AM

I have a flat 4 tester that you can plug into the vehicle and the LED's will light. Don't remember where I got it but it must have been cheap or I wouldn't have bought it. But it is handy. Just plug it in and you can activate the blinkers, lights, etc. and watch the LED's.

Silverton34 09-11-2012 08:55 PM

It's always the ground when things act strange.

ballistx 09-12-2012 08:04 AM

ground causing weird lighting
The reason for that is that the current is feeding through the trailer as a ground and back through the other lights. Ends up being a series/parallel circuit now with reduced currents. This causes weird results. That is why just estabilshing the ground between the vehicle and the trailer with the jumper cables corrects the problem.

Usually driving will correct it also as the ball hitch smooths out and makes the ground connection.

jetskier111 09-14-2012 12:13 PM

I appreciate the help. Im going to redo the ground this weekend and make sure the other wires are OK.

I will post how it goes.

THanks again!!!

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