Hi all,
2003 F250 7.3l, had it since '06.
not sure if related, but for years I had issue of window switches stop working. Might happen twice a year and I would open and shut driver door sometimes 3 or more times before working again or just drive and they start.
Now a few months ago normticed trailer running wire not working I've traced it underneath and to fuse box plug with test light. The fuse works with test light I'm guessing it's the f box....now after that crazy problems started....some instrument lights on left dont work no gauges work they were clicking and needles moving completely up. Radio yellow power wire doesnt get juice. And the window and sideview mirror switches dont work. Door ajar lights up on instrument cluster and caused the interior light bulb to staying on longer than usual before going off. It would come on go off and repeat. no idea where the door sensor for this is used to be a pin sticking Out on older vehicles but I can't find one to see if it is hung up. So my question is if I have a bad fuse Box, which I've taken out and taken partially apart but to no Avail to no Avail, Or do I have a problem with instrument cluster or something else what could affect the power window switches on all doors the radio and the interior light at the same Time. I've dug into some wires along the door that run up underneath the seat and across to the other side I've taken some door panels off and moved wires around bent up underneath the hood I cannot find anything thand anything that seems to show what the problem is not sure if the Brown wire with right stripe for trailer running lights is related to everything else or if it just quit working in the fuse Box maybe the fuse Box is causing these other issues

 

Did you notice any corrosion in the fuse box? (usually green fuzz)
Common issue is windshield leaking water onto the fusebox/GEM and causing havoc on most electrical components.

Door ajar switch is common failure, it's built into the latch mechanism. Sometimes blasting it with WD40 and closing the door a dozen times will take care of it, other times replacement is necessary.

For the windows and mirrors, check the threshhold wiring in the drivers door jam. The wire eventually fatigues and breaks. You probably have several failing/failed.

 

Does sound VSM or fuse box related but on the 02-03 models there is a junction box on top of the driver side fender that is known to corrode and disrupt power to the cab. Here's a picture of one that was bypassed (as a temp fix I hope), it's the light blue box. Might want to check that.

 

I will check junction box. Thanks.

 

I saw white corrosion only on 2 terminal slots for a fuse or 2 in bottom left corner area but 99.9% clean. It's a multi layer board no corrosion elsewhere. Had talked to fuse box repair guy online they repair the inside relays on boxes and said symptoms can be a range of things....also forgot to mention had to have a new steering column put in to replace ignition after truck was stolen 4 years ago. It could be in that for all I know. Just trying what would affect the radio wire the the gages the the interior light and door windows switches all at once you cannot turn the inside dome lights off when they come on using the roller switch as usual I have unplugged the roller switch it does not affect what's going on

 

Sounds like a problem with the VSM.

Here's a LINK to a good read on the subject.