SSharp

I can't get my running lights on my trailer to work. They all work while towing with my 2500 Dodge. The brake lights and turn signals work , but the running lights do not. Is there a separate fuse for the running lights I'm missing ?
Thank you for any help !

Steve.

Gene45

Did you look in the wiring part of the manual for the fuses?

Or check the plug on the truck for voltage. You can find the wiring for the 7 wire plug buy googling it.

SSharp

All fuses are good. New male part of plug. Every light on the trailer works other than the running lights.

NASCAR9

On the 7 wire plug the running lights are the brown wire. Use a 12 volt test light and make sure you have power at the plug.

depami

Is your Dodge trailer light wiring factory or after market?

I've seen where a trailer was wired to work with a non standard wired vehicle. In which case the trailer wouldn't work properly with other vehicles.

Also, how's the trailer ground? (White wire on the 4 pin connector, not sure on the other.) If you're grounding through the hitch weird things can happen.

It never hurts to use some Deoxit on all connections, including bulb sockets if they are not sealed units.

Steve Osborne

underhood fuse box... relay 6 for park lights.. fuse 67 for relay power..
pg 341..


http://www.fordservicecontent.com/Fo.../12f12og3e.pdf

depami

^^^ Well there you have it. Likely a blown fuse.

Gene45

Was the male plug added for the new truck? Are you certain that its connections are all correct?

And the suggestion to check the truck plug, is for the female portion to be checked with a voltmeter or test light.

There is no magic, just tracing down where it could be. Starting at the the plug, you can determine if the problem is in the truck or the trailer. Measure the resistance of the light circuit in the trailer with the plug disconnected. A very low resistance will tell you the circuit is good, high resistance will tell you that the circuit is not good, or the bulbs are all dead.

Measure voltage on the truck side with the lights turned on.

depami

Which connection are you using?

The four pin is pretty straight forward. There is more margin for error with the seven pin.

Check voltage between appropriate pins to verify that truck is supplying power properly.

deathbypsi

My 12 was same way when I got it. I bought it as a lease turn in by original owner and it had never towed anything prior to me buying it. No running lights at trailer plugs. All fuses good. I cut the brown wire in the harness behind the bumper and tapped into a liesence plate light wiring.