View Full Version : Trailer Lighting.. someone invent easy trailer lights!!

04-03-2007, 08:27 AM
I'm not very electrically inclined, but I know the basics. I HATE trailer lights, they work, they don't, one blinker works, one doesn't, etc. etc.

Well here's my prob. The lights work, but one side wont blink or brake. I'm confident it's a Truck Side problem because the trailer is brand new, and because it does the same thing with my other trailer. This is a 7-way round connector.

Anyone know where I should start to troubleshoot this?

04-03-2007, 08:57 AM
Buy a good test light and start with the plug on the truck. Test each function. If all ok go to plug on trailer and work your way back. I have found that most of the time problem is in the plug on the trailer or the back corner light that get back into.

If you find a problem on the truck just re-wire it. Trailer replace it(lights rust). For a diagram of the wiring just google it and hang it in the shop.

04-03-2007, 09:13 AM
How old is your truck? If you have a newer truck there are fuses for the trailer harness. Check to see if the fuse is blowen.

04-03-2007, 10:00 AM
How old is your truck? If you have a newer truck there are fuses for the trailer harness. Check to see if the fuse is blowen.

Start with what he said

04-03-2007, 02:53 PM
Start with what he said

My trucks are 99 and 2000, I'll check the fuses, then start checking each wire.... :hammerhead:

04-03-2007, 06:31 PM
I believe the signals are at 3 o'clock and 9 o'clock on the trailer plug. Use a circuit tester to see if you have power on that pin.

04-03-2007, 06:47 PM
some require a splitter off the truck.

04-03-2007, 07:36 PM
Print these out and hang em and save um


04-03-2007, 09:17 PM
I feel your pain. It seems like every trailer is a wiring nightmare!

gammon landscaping
04-04-2007, 02:09 AM
when ever i have problems it is always the same thing. i spend 4 hours trying to see what is wrong, then i get mad and get out the wire cuters and cut it all out and replace all those cheap crimps with soider and shrink wrap. oh yea don't ever buy the trailer lights with bulbs that are replaceable. they will rust by the time the bulb burns out. go to a tractor trailer shop and buy the sealed lights that the big rigs use. they are about 5 bucks and it is lens and light and all, when you crack it or it burns out just replace the whole thing and no worries

04-04-2007, 10:00 AM
I have found a multi-tester has been a great tool for me to troubleshoot trailer wiring. I always know the status of power/no power, grounding/no grounding, etc. I have a very simple one from Radio Shack, probably less that $15.00.

Can we presume you have a standard 4-wire configuration?

With regard to trailer lighting fixtures, I changed out my bulb fixtures a year ago, in favor of LED fixtures. The blown bulb problem is gone! Yes, the initial cost of the fixture is more, but they were solid for a full season, much more than I could say for the bulb-based fixtures. However, if you are having problems of the simple facets of power to the fixture, a change of fixture will not solve any part of that problem.

04-04-2007, 10:24 AM
my trailer still doesnt have lights on the right side, i checked all fuses and tested the plug on the truck. next comes re-wiring the lights on the trailer. i wanted to put some extra ones on there anyways.