how to keep on interior lights on

[socks999]

right it might sould silly but
some time i have to sleep in the back of the van which is fine has it all borded out and roof so not to cold plus small heater.
the thing i have is
it you out the light to the middle the lights stay on for about 15 mins then go out
i have to open the side door then for a extra 15 mins which then lets all the cold in.
i have the back full strip light so like home from home
just the light go out
i can not leave the keys in has i am in the back
any help if poss
thanks.

[Graham Taylor]

Fit a set of LED's with a switch