Trailer wiring question...

#1
Ok, So on my m416 trailer I rewired it with standard trailer lights from northern tool...well they work exactly as they should when I dont have my headlights on on the jeep. When I turn my headlights on on the jeep the trailer tail lights go bright and the blinkers dont work... I followed the wiring diagram that came with the lights as everythign was color coded...what did I do wrong?
 
#2
I've never wired up a TJ but if it's like an XJ you'll need a convertor for them to work correctly with the lights on and off. My old XJ has this u-haul box that does it's little magic. My current XJ doesn't have said convertor and works properly during the day but when I turn my lights on the running/park lights do not work(everything else does). I think this box converts it from 5 wires to the standard 4. I dunno though, just a guess.
 
#3
I guess the first question i should've asked is "has it ever worked properly"? When you rewired it did you change anything or where it ties in to?
 
#4
Brooks, could you link to which lights you bought? I suspect Team infidel is right. It sounds like you are trying to dual purpose a light that isn't designed to be dual purposed. The second thought is a bad ground on either the trailer wiring harness or the vehicle trailer umbilical cable, they will do some crazy crap with a weak or broken ground. I've got some skill in this department if you can provide me with a little more info.
 
#5
I bought this kit, and I do not have any sort of box on the wiring, I merely tapped into the wires and made my own harness on the jeep. My wiring works on other trailers, just not this one. It worked on our jeep tub trailer and it works on my dads boat, and enclosed trailers.

http://www.northerntool.com/shop/tools/product_371254_371254

also note, I started from scratch on this trailer as the old wires were rotted and it was wired for 24volt lights.
 
#6
I bought this kit, and I do not have any sort of box on the wiring, I merely tapped into the wires and made my own harness on the jeep. My wiring works on other trailers, just not this one. It worked on our jeep tub trailer and it works on my dads boat, and enclosed trailers.

http://www.northerntool.com/shop/tools/product_371254_371254

also note, I started from scratch on this trailer as the old wires were rotted and it was wired for 24volt lights.
after reading the two reviews on the northern tool site, it seems I may just not have a good ground on the lights themselves. they mount to the stock metal bracket on the frame, but I guess I need to check the ground.
 
#7
Check the power and ground at the plug on the jeep. You can use a test light or multimeter. Once you are sure that's good, then you can use a set of jumper wires to check the wiring on the trailer. I think you are correct in thinking there is a faulty ground.
 
#8
Check the power and ground at the plug on the jeep. You can use a test light or multimeter. Once you are sure that's good, then you can use a set of jumper wires to check the wiring on the trailer. I think you are correct in thinking there is a faulty ground.
well I know the jeep side of the plug is good because it works on the 2 other trailers I pull
 
#10
Sounds more like your stop/turn and running light wires are crossed on the trailer. With the headlights/running lights on the bright filaments are powered. These should be the turn signals and brake lights. The dim filament is powered by the turn signals/brakes which would still look OK during day time use, but wouldn't be as bright as they should be. At night with the headlights on the dim flasher would be barely noticable.
 
#11
Sounds more like your stop/turn and running light wires are crossed on the trailer. With the headlights/running lights on the bright filaments are powered. These should be the turn signals and brake lights. The dim filament is powered by the turn signals/brakes which would still look OK during day time use, but wouldn't be as bright as they should be. At night with the headlights on the dim flasher would be barely noticable.
that is possible if the factory wiring colors do not match. I connected color to color. I plan to check it out one night this week.
 
#12
3+1 trailer wires are pretty simple in themselves. The +1 is the ground; the 3 are (in no order): Parking (both parking lights on same wire), Left, Right (blinkers). The Left + Right blinkers, when both activated, are your brake lights.

If you have a spare battery, or even a battery charger, hook up the negative to the "+1", and use a jumper wire to activate each line of the +3 and verify that they all work.

Then you can use a voltmeter to check the Jeep side, and verify that each of the "3" is getting current. Make sure that they match with how the trailer is wired.

The problem with the Jeep is that you can't tap straight on the tail/blinker/stop lights, as they are sensitive to load. That's what makes the blinker blink slow or fast when a light is burnt.

JP
 
#13
3+1 trailer wires are pretty simple in themselves. The +1 is the ground; the 3 are (in no order): Parking (both parking lights on same wire), Left, Right (blinkers). The Left + Right blinkers, when both activated, are your brake lights.

If you have a spare battery, or even a battery charger, hook up the negative to the "+1", and use a jumper wire to activate each line of the +3 and verify that they all work.

Then you can use a voltmeter to check the Jeep side, and verify that each of the "3" is getting current. Make sure that they match with how the trailer is wired.

The problem with the Jeep is that you can't tap straight on the tail/blinker/stop lights, as they are sensitive to load. That's what makes the blinker blink slow or fast when a light is burnt.

JP
Mine are not sensitive to load any longer because when i put my LED tail lights in I did the mod to the circuit where it doesnt know if a bulb is burned out because the LEDs draw so much less amperage.

As I said too, the wiring on my jeep works for 2 other trailers that are wired from the factory, so I know its something on my trailer wiring.
 
#14
Mine are not sensitive to load any longer because when i put my LED tail lights in I did the mod to the circuit where it doesnt know if a bulb is burned out because the LEDs draw so much less amperage.
Fair enough. No worries there.

As I said too, the wiring on my jeep works for 2 other trailers that are wired from the factory, so I know its something on my trailer wiring.
Likely the trailer. Give the trailer wiring a test like I explained. From your explanation, sounds like the blinker/stop are swapped with the parking lights. When you turn on the parking lights, the brake lights are being activated, and when you mash the brake pedal, the parking lights are coming on, but compared to stop lights, they are much dimmer and you're not seeing them.

JP
 
#15
Fair enough. No worries there.



Likely the trailer. Give the trailer wiring a test like I explained. From your explanation, sounds like the blinker/stop are swapped with the parking lights. When you turn on the parking lights, the brake lights are being activated, and when you mash the brake pedal, the parking lights are coming on, but compared to stop lights, they are much dimmer and you're not seeing them.

JP
that sounds like exactly whats happening when I have my lights on. In the scenario would they work properly with my lights off?
 
#17
I dont think this is the case though, I'll have to look. I'm pretty sure when I have the headlights/running lights off the brake lights and turn signals on the trailer function as normal. but I could be mistaken. I'll check again sometime this week.
 
#18
well I know the jeep side of the plug is good because it works on the 2 other trailers I pull
Agreed, but have you used jumper wires and a meter to isolate the trailer wiring and check each circuit separately? That's the key! If the ground on the trailer is faulty, the circuit will be grounded through the hitch and that's not sufficient. That will cause it to backrest through any other unused circuit as it will be searching for a ground.
 
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