Dome light circuit on '90 Ranger

[scotts90ranger]

How does it work? A couple years ago the dome light quit working with the passenger door, a couple weeks ago the dome light quit working with the drivers door. The light works with the headlight switch. I figured it would be the door jamb switch, replaced the drivers side switch and still doesn't work. I think I remember something about the circuit going through the headlight switch? Where do the 3 wires on the switch go? I didn't look too close at the 3 pins, I did look close enough that they aren't corroded or broken off... I'm assuming orientation doesn't matter as there was no keying on the switch connector...

 

[RobbieD]

Ford switches +12 volt to the dome light, so the door pin switches are hot all the time. Check fuse 1, as it's easy to short a pin switch when you R&R one.

1990 schematic:

 

[RonD]

Passenger side is just 2 wires, 12v IN all the time, 12v OUT to dome light when door is open

Drivers door is 3 wire, 12v IN all the time, and 12v OUT to dome light when door is open
3rd wire is 12v OUT to Chime module but Chime module must also be grounded to "chime", grounded by key in ignition usually

The Main light switch dimmer can also turn on Dome light and uses same fuse, but different wires, so if its working then fuse is OK, and wire up to dome light is OK
So an issue with door switch wiring, either no 12v IN or 12v OUT wire is bad, you can pull the switch again and jumper the green/yellow and black/blue wires together on either door switch and dome light should come on

New switch just means NEVER EVER tested switch, lol

 

[scotts90ranger]

Thanks guys! That gives me somewhere to look at least. Whatever it is is inconsistent, I spun the switch button thing a couple weeks ago and it worked once then stopped... I had a headache most of today so didn't have much patience and was hoping to find exactly what you guys posted!

I'm with ya Ron, new doesn't mean good anymore... I figured if it was 3 pin and non keyed it had to be something like power in and two power outs at least on drivers side so 3 contacts with one contact to connect the other 3 or TPST NC in switch lingo...

 

[rubydist]

Your symptoms suggest a bad connection or open in that circuit somewhere.

 

[RobbieD]

Another thing to check; will the dome light work correctly by pushing the pin switch with your thumb, but not by opening the door?

If memory serves, Ford pin switches from that era were self-adjusting (new switches came fully extended, first close of the door adjusted the switch throw). The plastic pin switch is in a tube that can slide in the threaded mounting nut. Over time the pin switch can go out of adjustment and not protrude far enough. If it works with your thumb but not the door, try pulling out on the pin/tube part gently with some pliers, so that the door can again depress the plastic pin.

EDIT: never mind; that fix is for the dome light NOT turning off.