I have an 02 that I bought almost 2 years ago. The brake and turn signals work, but no running lights. I've never needed to use my trailer at night till now, so I need some help if anyone has had an issue like this. I've tested the wire almost to the firewall and haven't found a problem. I unplugged the wiring harness under the air intake at the fender and there is no problem from there to the 7 way plug. The brown wire is the one I'm having trouble with. Thanks for any help.

 

Check fuse F5 and the trailer tow running lamp relay in the under-hood battery box. They might not be installed.

 

Both fuse and relay are good.

 

You'll have to test the circuit the old-fashioned way - with a meter and the schematic. You've checked all the easy stuff.

 

Well, I should have payed closer attention to your post. I checked fuse #5 under the dash, not in the under-hood box. Just found fuse #5 under the hood is bad