Answer
May 02, 2025 - 01:53 AM
Yeah, that’s a pretty common issue on these trucks, especially the older Super Dutys like your 2004 F-350. When the dome or cargo light comes on and off by itself, it's usually not the light itself, but rather one of the door ajar switches acting up. Even if all your doors are closed tight, the switch inside the latch can get dirty or sticky and randomly tell the truck that a door’s open.
Most of the time it’s the driver’s door or rear doors on crew cabs, but it could be any of them. You can try spraying a bunch of electrical contact cleaner or penetrating lube directly into the latch through the little access holes while working the door open and closed a few times. That clears up the problem more often than not.
The repair manual also covers wiring diagrams for the interior lighting and door switch circuits if you want to dive deeper and test for voltage at the Smart Junction Box (SJB) or check for a fault in the switch itself. So if those tricks won't do it, maybe checking the wiring diagrams would be the next smart move. It also has troubleshooting procedures for electrical problems like these, so you won't be left in the dark.
Good luck!
