2002 F150

Trailer running lights not working… No juice from Brown lead on truck connecter… Breaks lights, turn signals and flashers work. Could it be a fuse or a relay? Thanks for any help!

 

http://www.fordservicecontent.com/Fo.../02f12og4e.pdf

Start on page 205. Fuse and relay locations.

 

Got it thanks for your help… I'll check it out! Looking at the fuse's in my truck they all are good. How do you test the relay's? Thanks again...

 

You can't tell if a fuse is good by just looking at it. You have to measure voltage on both sides of them. You test relays by substitution.

 

Thanks again for all your help, I'll let you know how things work out.

Have a good one...
Chipste

 

Dumb question time from me.

Is the parking lamp on the trailer tow adapter brown or brown w/ white stripe ?

The factory color code is brown w/ white stripe.



Next is to check the fuse that powers the trailer tow running lamp relay.
Battery Junction box fuse #5: 20A.
- Test it in the fuse slot from a known good ground to each pin on the back of the fuse.

If that tests good ( + VDC on each pin ) is to check at the connector by the spare tire.

You will need to drop the spare to get the connector apart and test it.



If I recall correctly, this is connector C411 in the diagram above.
- You are testing the Brown w/ white stripe wire for +VDC when the truck's parking lamps are on ( that is what powers the coil on the trailer tow running lamp relay ).