geode

Greetings Everyone. I have exhausted the Internet and the forums so this is my question. My dome light stopped working and the lights in the box also died. The fuse is fine, not the over ride, I have voltage at the fuse but nothing. I disassembled the dash looking for the Courtesy light solenoid to replace but I can not find it for the life of me so I dont think it exists on the Cutaway van. I did find solenoid bank over the steering column but there was only one solenoid in the slot that had tape on it from the factory. I assume this is the hazard (didn't think to verify that when I was in there) but no courtesy light solenoid anywhere so I assume this is built into the headlight / instrument dimmer switch. Now I did have problems with the dimmer but once I cleaned it with CRC that problem was resolved. My question is this, Would the power pass through the headlight switch first before hitting the Box light. I have a new switch en route from Rock Auto but want to try all alternative fixes in case that is not it. Thank You in advance,

mountainmanjoe

I think you mean relay, not solenoid.

interior lights are always powered. They are switched on the ground side.
Did you open the lens housing to inspect/measure for voltage there?

geode

Yes, solenoid. I just checked voltage at dome. 11.3 V with dim switch set normal. 4.2 V with dim switch click up all the way.

Thanks for the fast response MMJ

mountainmanjoe

a solenoid is just an electromagnetic coil. When you put it inside an electrical switch with contacts, it becomes a relay.

Was that measured with the bulb in or out?
So you just measured the ground side right? (white wire)
What does the orange wire read?
(always measure with respect to a clean chassis ground)

geode

Measured with bulb out. I can not see the wires since they are up behind the light but it is the positive side (there is a spade with a hole for accepting test lead I presume). The voltage fluctuates with turning head lights on and off, which shouldn't happen. Also, these are readings from the cab dome.

mountainmanjoe

sounds like a faulty ground on the headlamp switch

geode

Thank you, Joe. Since the head lamps and instrument lights are working I assume the faulty ground is inside the switch and it is only hindering the dome. New switch due in a couple of days so I'll just wait, swap it out and not go ground hunting. I did not test voltage on cab light system and wont have time tonight. For now hoping they are tied together through headlight switch. Thank You again Joe. Appreciate any other thoughts and will get back with final result.

geode

NOTE Cab light should read BOX light. I could not edit for some reason

mountainmanjoe

Nope. They will still work with a bad ground. It just means the headlamp circuit is back-feeding into your dome light circuit and grounding through it instead of the switch, and it's messing with your interior lights.
I would suspect the ground point before the switch actually.

geode

Damn. Any suggestions as to where I should start the hunt? I may add that, although it is an older vehicle, i purchased it new, it is in pristine condition (for a work truck) and only has 141 K in it. Nothing has been altered short of a stereo upgrade when purchased. I visually inspected the harness by the emergency brake area. Everything looks pretty solid. maybe there is a point known to fail ?