H3 or H3T with manual transmissions

[Bosshoss]

Couldn't figure out dome light on mine for a long time, dealer said it was lights I put on front of truck (in other words they couldn't figure it out either).
Found that if I shut truck off with key before it quit rolling dome light wouldn't work. Try to make sure truck is stopped before switching off key and see if that works on your truck.
Good luck
Paul