Hello,
I am having some problems with my tail lights on my '89 F-250. They work when you turn on the trun signals, they work when you apply the brakes, but they dont work when you turn on the headlights (like a parking light sorta deal). It just started doing this today.

Any ideas???

TIA
Storman Norman

 

The brake/turn signal portion is a separate circuit from the running/parking lamp circuit.

Do your front marker/running lights work or are they also off?

Steve

 

Fuse #4 is bad, a 15 AMP fuse.

http://i54.photobucket.com/albums/g9...nel/88Fuse.gif

 

Thanks sudford, I'll go get a 15 amp fuse while im out tonight.

Steve, yes the front lights work.


Storman

 

If the front parking lights work then the Fuse is good.

 

Yea its not the fuse. I just tried that. Im gonna replace the bulbs. If it doesnt work, o well. When it does work, I wont have to worry about bulbs then.

 

Your description is a little vague. I am going to guess your turnsignal and brake lights work as you described, and when you turn the headlights on, the taillights do work, but the turn and brake functions will not. The turn and brake functions will work again when the taillights are off.

If this is the correct senario, then it's the classic grounding problem for the rear bulbs. It can be the bulbs are corroded in the sockets, or the ground from the socket to the bed is bad.