99 f350 long bed 7.3 diesel

Sorry to he posting another one of these but I wasn't finding any answers in the ones I had read threw.
For beginners I bought the truck with the problem. I have a shell so the bed lights have been removed or burnt out. Haven't checked.
I have already tried the WD40 trick in the door latches and nothing
No door ajar light. Most likely burnt out since there's nothing on the dash when the door is open.
The odd ball thing and someone referenced it but didn't discuss it: the dome light does go out if I am going 10-15 mph but turns on when I am breaking to a stop.
With the bulb removed I can hear the relay activate and deactivate with the speed.
So any ideas?

 

The only thing I can tell you is the truck thinks a door is open. They will deactivate at a certain speed because it knows there is a problem if your going 15 with a door open. You will have to hunt down the bad switch/wiring.

 

I resprayed all the door latches with carb cleaner,let them dry out then resprayed with WD40 and went on an hour drive to make sure my mom was doing ok and let her see the grandson. Lights still acted up on the way there.
Once I was coming home it worked itself out.got off the freeway and noticed the light didn't come on. Played with the switches and opened/closed all the doors multiple times. Works like a charm.guess I just needed more resolve and patience.
Now onto the next problem.

 

Thanks for posting your resolution. I'm having the same problem with my 1999 F250. I've been trying to isolate which door is causing the problem but it doesn't seem to be related to either one. I'll try the carb-cleaner trick and go from there. Thanks again.

 

I called my friend who is a Ford authorized mech. He said that's what they do at the dealership.sometimes you have to pull the panel and do it from the inside.but that only takes a minute.

 

I always break stuff when i pull door panels, but I'll give it a shot. Thanks again.

 

I wonder if now that this is working of I can get my rke to program.going to tty after the baby goes to sleep

 

Nope didn't work

 

I have a similar problem. My dome light doesn't come on. It won't come on with the dimer switch either. I changed the relay and no change. I did run a jumper to the second post where the relay would plug in and the light worked fine. I have tried spraying the drivers door latch with carb cleaner and WD 40 but nothing worked so far. Any ideas would be appreciated.