I’ve got a 1999 Chevy 3500 four door. This has a dome light in the center and rear of cab. Also has the light switch with the dome override button and a wheel that adjusts the brightness of the dash lights and turns the dome lights on while doors are shut. The four courtesy lights on the doors turn on when door is open but not the two dome lights. These domes use the big glass fuse as a bulb. The center dome has one in it and it’s a good one, did continuity check. The contacts that this fuse sits in are both showing ground with door open or closed. The rear dome doesn’t have a fuse in it. It’s contacts show ground on one end and nothing on the other. Also the contact that shows nothing is pretty loose, not tight like the other. Any idea what’s going on with these dome lights so I can finally get them fixed?