Dome Light Switch
1) The dome light switch in each door jamb, to turn on the dome light when either door is open.
2) The headlight switch, to turn on the dome light with the headlight **** turned all the way to the LEFT.
Both switches feed the BLACK with BLUE stripe wire, which is the signal that goes out to the actual dome light itself. The dome light grounds through its bulb carriage, which screws into the roof sheetmetal.
1) Make sure you have 12 volts on both sides of the courtesy lamp fuse. This circuit is hot at all times, so it doesn't make a difference what position the key is in. If you have power on only one side, replace the fuse. If you don't have power on either side, then there is other work to do first.
2) Pull the dome light switches out and remove them. Make sure the terminal for the GREEN with YELLOW stripe wire in the connector has power.
3) Check the dome light switches for continuity. With the plunger all the way out (switch CLOSED), the switch should be shorted. With the plunger pushed all the way in (switch OPEN), the switch should be open. If not, replace the switch.
4) With power to the switch proven to be good, and the switches proven to be good, the dome light should light up. If the dome light does not light up, remove the cover and check for power at the dome light (not the side that's permanently grounded to sheetmetal) with the door OPEN. If you have power here, yet the bulb does not light up, replace the bulb.
This will prove out the door-side; if you get to the point that the doors turn the light on but the headlight switch will not, then we can cross that bridge.
Again, you will need a multimeter to do this, unless you want to try and get lucky by just replacing things off the bat (which may work too).
The switch just connects to the connector that's already in your wiring harness. Just unplug the old switch, and plug the new one in. If your harness's connector is gone, LMC (and others) sell replacement connector ends to splice into your harness. I responded to that question in your other thread. Try to keep all your questions about this topic in this thread; it's easier for people to keep track of.
If you get new switches, I'm sure it will all make sense to you how they go in.
Trending Topics
Ford Trucks for Ford Truck Enthusiasts
If the wires will not physically stay in the connector that's part of the truck's wiring harness, then you'll have to splice in a replacement connector.
I recently purchased my third Aerostar, a 1997 XLT. It came with a tiny, unswitched, rear hatch lamp. It comes ON everytime the hatch is opened, but sometimes I want it OFF when the hatch is left open.
I found a Switched lamp assembly from an older Aerostar; It has a 3-position switch: ON-OFF-DOOR. It also has 3 wires. The dome lamp I removed has 2 wires only.
The new switched lamp has no factory provision to ground it to the body, no mounting screws, no grounding tabs, nothing. It is held to the headliner panel by spring clips and double-sided tape on two "feet". (there are two screws that hold the Lens to the lamp assembly to remove the lens for bulb replacement).
It would seem to me that the third wire might be in the main wiring harness but taped and disabled; Hard to see or get to the main harness without removing the headliner panel.
short of a headliner disassembly and a wiring harness fishing expedition, how can I wire-in this new lamp with only the two available wires?
Thanks for any help.
You might get a better answer if you asked it in the Aerostar forum.
Aerostar - Ford Truck Enthusiasts Forums
MSRP: $18.60 // FTE Ford Dealer Parts Dept sponsor tousleyfordparts.com price: $9.21.
Applications: 1973/79 F100/350 / 1978/79 Bronco // 1975/80 Granada/Monarch (R/L F/R) / 1976/77 Maverick/Comet (R/L F/R) / 1977/80 Lincoln Versailles (R/L F/R) / 1983/86 LTD/Mercury Marquis (R/L F/R ~ mid-sized Foxes).
1983/94 Ranger / 1983/95 Mustang/Capri / 1983/97 Thunderbird/Cougar / 1984/89 Bronco II / 1986/92 Aerostar / 1986/94 Tempo/Topaz (R/L F/R) / 1986/95 Taurus/Sable (R/L F/R) / 1989/02 Continental Sedan (R/L F/R).
1990/96 F150/350 & Bronco / 1990/95 Lincoln Town Car (R/L F/R) / 1991/01 Explorer (R/L F/R) / 1992/95 Crown Vic/Mercury Grand Marquis (R/L F/R) / 1997/01 Mercury Mountaineer (R/L F/R).
F/R = Front & Rear doors: Look for the above 4 doors in wrecking yards, remove switches from rear doors, will be like new.












