You need a fused live and a switched earth (from door switch) running to cab light. You can earth the light switch (for on all the time) in the cab roof. Cable down the B pillar for the sliding door switch, which can either do the cab light or rear interior light. Front doors: just run a cable joining the two switches, so they're connected in parallel.
thanks for the input guys....investigating luminous paint and torches.... switch contacts are good....LED festoon already installed..looks like it's a peel back the headliner job
Can't beat a good festoon! Taking down the side of the headlining is pretty easy, if you have to do it.
But you need to stick something like a cable tie in there to stop the little LED festoon PCB going round and round when you operate the three way switch in the dome light , otherwise it gradually walks round until it is lighting up the inside of the fitting.
yeah handy cos it comes on and stays on where needed fink I got from Blt or was that what I had for b,fast. Just hope no one else on campsite has one or it could ******* you right off.
could be fun, when folks have gone to bed... in fact I may just buy one and seek your van out at a show, around 3 AM....
Why not fit a discourteous light instead? I've got one that mutters "c**t" every time I open the cab door. Just a thought !