Interior lights stay on, and rear bed lights, which are on the same circuit, unable to find circuit diagram in any manual I have for F150. Door ajar light is not on, there for I would think door switch has nothing to do with it. I know there is a timing circuit but again, unable to find diagram. Please advise and thanks
In the junction box relay panel there is a 15 amp fuse number 14. This is the fuse that controls the Battery Saver Relay, Interior Lamp Relay, Generic Electronic Module (GEM) / Central Timer Module (CTM) and also the Interior Lamp Switch.
Start by unplugging the number 14 fuse to see if the lights go out. If they do then install the fuse again and you can start unplugging one relay at a time to see if the lights go out.
It could be a stuck relay/module or a bad interior lamp switch.
If you need to get a wire schematic, you can get one at ALLDATAdiy.com