I recently acquired a 1991 250 w/318 and I think an A518. I am having issues with the tail lights not working. The brake lights and turn signals work, but when I turn on the headlights, nothing. At first I thought the previous owner had just let them both burn out, but he insists they both just quit working one day. Is there a separate fuse or circuit for the rear running lights I can look at?

I would prefer to be able to drive this truck at night without being pulled over, so thanks for any help.

 

have you checked the ground wire that goes to the rear lights? if they work when your headlights are off but don't work when your headlights are on they may be pulling ground from marker light wire when they are off.

 

Insofar as I can tell they don't work at all, thought the turn signals, hazards, and brake lights work. What fuse do they run through? And where is the ground wire?

 

so just the headlights don't work?

 

The head lights, brake lights, turn signals, hazards, and reverse lights all work. What doesn't work are the running lights in the tail lamps which should come on when the headlights are turned on. The tail lights use either 2057 or 1157 bulbs (mine has 2057s) which have two filaments, one for the blinkers, brakes, and hazards, and one for the running lights which come on when the headlights are turned on. The running lights don't come on.

I pulled out the fuse block and checked the fuses. The fuse plug (where it plugs into the block) for the dash lights is burnt and the fuse is partially melted. I read somewhere else that the dash lights and rear running lights go through the same fuse. The block does not indicate this.

Any ideas?

 

if your headlights are working then your running lights should be working. the dash lights are on a different fuse but also get there power from the headlight switch. do the running light up front work?
this might help you figure out what fuse you are looking for

 

Ok, the schematic is very helpful. Thanks for posting. If I am reading this right, fuse #8 is the second from left under the turn signal flasher. That plug is burnt and melted on the power side. However, I believe this is a symptom of a larger problem.

Crap.




The image is sideways. Left is top.

 

Next question: Has anyone successfully wired their running lights around the fuse block and if so, how?

Bless your heart if you have pictures and post them.

 

Lights fixed. Thanks for the help!

 

OK.....great! Now tell us all how you did it! That is how these threads work....and oh, cool you got er done!