Does the horn work? The horn and the interior lights are on the same fuse. If the horn works okay, the first suspect is the interior light switch, but not all vans use that. It is a dash switch that, when turned off, prevents any interior lights from turning on.
You need to have full battery voltage on one side of each interior bulb. You'll find it on both sides if all the door switches are turned off, meaning all the doors are closed. That 12-volt feed wire is the orange wire. The white wires go to ground through any of the door switches.
As shown on my diagram, some of the overhead interior lights only turn on with their individual switches, and they have their own ground circuits. If the dash switch is defective, those lights also will not work, in addition to the lights that turn on when a door is open.
Monday, December 5th, 2016 AT 7:40 PM