Hi, I have a 2000 3.0L 5-speed Ranger and my dome light does not come on when I open either door's. It will come on with the dimmer switch, am I looking for a specific fuse, relay or door latch sensor?

 

If the dimmer switch is activating it, then the relay isn't your problem. If only one of the doors couldn't activate it, then it would be a door sensor. Check your fuses first. There's a box on the driver's side on the dash under a lid. Check each one there for a blown fuse.

 

I just checked all fuses including the one for the battery saver relay/dome light and there all good. I took the dome light and found two wires a green/yellow and black. The green/yellow has 12 volts all the time and the black has 12 volts when I use the dimmer switch to turn on the dome light. Not sure what to make of that, hopefully someone can weight in on the situation.

 

Map and Dome lights are usually Grounded locally, to cab metal, make sure ground is good.

The green wire is for the Map lights, Black wire for dome light.
Green wires should have power when key is on, and for about 20min after key is off, these are controlled by switches in the overhead.
Black wire will have power if dimmer is on, voltage varies with dimmer setting, and voltage should switch to full 12volts if door is open

The door switches run to the GEM module, they are Grounds, so when door is open GEM "sees" a ground on that wire, it then Grounds the interior lamp relay to activate it, this relay passes power to the Black wire.
When this relay is open then power comes from the dimmer switch.

Key on with doors closed check voltage on black wire and use dimmer control to turn voltage down a bit
Now open a door you should hear this relay click closed and voltage on black wire should jump up to 12volts(battery voltage)

All the lighting power comes thru the Battery Saver relay so it is working if you show voltage on green wire, battery saver relay stays "on" for 20-30 minutes after key is turned off.

The Interior lighting relay is in the same box as battery saver relay, it is called auxiliary relay box 1
Not sure on a 2000 but it is often found just above gas pedal location, but also behind radio


This is a 2001 diagram and should be same on yours:

 

My dome light didn't have a bulb in it when I got my truck, and I recently found out why. If my truck is running, the light is on. If it is running with all doors closed, locked, unlocked, it doesn't matter, the light will stay on. I'm assuming this is because it is wired directly to the battery? I figured putting in a switch will do the trick. I just find it weird that the doors being open/truck being locked or unlocked has no effect on the light.

 

This happened to me. One of the door latches was stuck and my truck always thought a door was open. Try spraying WD-40 into the door latches which hold your door shut and opening and closing them a few times.

 

yes, stuck or broken door latch.
It is a Ground so doesn't "short out", if latch is grounded GEM turns on dome light

 

Thanks RonD for the information and diagram, I will order a interior lamb relay to fix my problem, I just confirmed that both door latch sensors are working but no power is getting sent to the black wire and I do not hear a relay click when opening a door.

Marc.

 

It should just be a standard 5 contact automotive relay, available at any auto parts store.
12volt, 30amp

Yes, the light relay would be most likely issue since dimmer works, but..............

GEM module does need to Ground that relay to close it(click) and send 24/7 power to bulb

Automotive relay info here: Automotive Relay Guide | 12 Volt Planet
The Standard is world wide

 

I will go ahead and order the relay from rockauto and hope for the best. Thanks for the link I will look into it if I have more issues with relays.

Marc.