2001 F350 PS, Crew, 8' bed.
What could it be?
I just replaced all the bulbs, and the fuse is good.
What else could it be?
The lights are supposed to come on when you open the door, or.......
activate the interior dial/switch by the headlight switch.
Nothing.
The map lights all work and all other lights on the truck work.

 

Should be a relay in that circuit. don't know were. look for a schematic.

 

I have the opposite issue, the lights won't go off....I ended up yanking the fuse.....so I'm permanently in stealth mode now....I'd check for power at the switch in the dash....if you have power there then the issue is down stream towards the bulbs....if no power at the switch, then it is further upstream towards the fuses...

 

Fuse number 14 under the dash and relay number 1 under the dash control the interior lights on your truck. Swap the relays around and see if that helps.

Spray your door latches with WD40. Probably a stuck door switch (mounted inside door to latch) so us plenty on each door.

 

I would suspect relay at this point. And even if the door switch was stuck, shouldn't you be able to turn them on with the interior switch on the dash?

 

Yep, that answer was for gofast whose lights stay on.

 

Theres also another fuse that does that, I believe its called delayed accesorry. When it goes out, your radio also doesnt work. The clock may though. Cannot remember now.

 

Thanks for the info.....I've heard that before, but it's one of those thing's I havn't gotten around to yet....Just thought it was funny that someone else would have the opposite problem I had.....thought we could trade "luck" and fix each other's trucks......ok, over....

 

I have the same problem. I have changed the relay and no change. My dome light doesn't come on when I open the door or when I turn the dimmer switch all the way up. My 2 map lights both work. I did shoot the drivers door with carb cleaner and WD-40, and that didn't help. I don't know why the other doors would matter. If I can get the drivers door to work, I can figure which other doors don't work. That doesn't seem to be the problem because the dimmer switch should turn it on. All bulbs and fuses are checked and good. I have jumped a the 2nd post on the relay with a hot line and the lights did come on.