I wasn't sure where to post this thread so I am posting here. Anyways, I have a 98 f 150 with orp. My problem is the running lights do not work on my truck. The stop lights, turn lights, parking lights all work fine. I thought maybe it was my trailor so I tried it on 3 different trailors and none of them worked. Any ideas what might be causing my running lights not to work. They used to work perfect.

thanks
Justin

 

There should be a separate Relay for your running lights on the trailer - check to make sure that is OK. Should be under the hood in the electrical relay box

 

just went through this on my 98. under the hood by the master cylinder there are two taped black retangular boxes. inside these boxes are fuses and relays for the trailer lights. if you look in your owners manual it will tell you which fuse is for what. if not just pop each one and test it. it's usally not the relays so don't worry to much about them. i had the same problem and after a week of testing wires i finally found an old tread on this site and gave me the solution. the boxes are hidden pretty well and usally taped with electrical tape. cut the tape and snap open the boxes, you'll be a happy camper

 

Tele has the right idea. I am one of those few who had a bad relay and that effects the blinkers and break lights. Check the fuses. Also check the contacts on the plug and make sure the one that feeds the running lights is not caroded.