Welcome to iRV2. I do not know your coach. Somewhere there is a 12VDC fuse buss for almost all the automotive fuses. On my coach it is in the most forward basement bay on the driver's side. You'll, most likely, need a magnifying glass and a flashlight to determine which fuse goes where.
Do the lights work at all (during the pre heat wait)? With just the ignition on and not trying to start?
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
The Avatar Is Many Times Around The USA
Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours