Dome light housing

[1968flareside]

I've been chasing down the last few electrical gremlins today. The only one I can't figure out is the dome light. When I look at my diagram specific to my truck, 1968, it shows a ground wire and power wire from the assembly. Mine only has the power wire. The problem I'm having is that it stays on all the time. I even tried two different brand new headlight switches, so it's not that. I'm beginning to wonder if this dome light assembly is from a different model. The only wire does say FoMoCo on it. So it's not aftermarket. Any ideas?

It looks just like the one here from a 1967...

http://www.fordification.com/images/sch ... lights.jpg

[bluef250]

A thought, make sure the interior light wire to the switch is in the correct position. Some of the positions on the switch on hot all the time. PO may have been doing some work and got wire to wrong terminal.

[1968flareside]

blue,

I did the wiring per the directions from Painless and my 68 wiring diagram. There simply is not a ground wire from the dome light housing as shown in the diagram. I do, however, understand what you are saying.

The dome light never worked when I had the original harness in. It seems like the original was replaced with the current one.

[fordhombre]

The dome housing is probably just using the metal housing as a ground. The bulb will be in contact with the dome housing, and the housing will be set to the metal cab. As long as your cab's grounded, the dome light will work.

As for it being on ALL the time, were there door jamb switches that are broke, maybe putting out a constant signal? Also, is the headlight switch turned all the way down? It could also be that the dome light power wire is connected to the wrong wire in the headlight harness. I believe the wire from the harness is blue with a black stripe. Maybe there was no stripe, but i'm sure it was blue on mine (69 f-100).

Try checking that wire, door jambs, and the headlight switch position.

[mercman1953]

Ford almost always used power side switches. Look at your door switches. If they have two wires there is probaly power there. If there is then you need a dome light housing with two wires. It sounds like you may have a later model housing. mine on my 68 has two wires.

[Mytmos]

On my '70 I have a single wire dome light grounded by the housing to the cab. I went out and checked if I unplug the door switch the dome light goes out, but also I can turn it back on with the headlight switch. So try unplugging your door switches first and if it still stays on start looking at the headlight switch.

[1968flareside]

I have already removed the switches, but did find out my headlight switch was bad. I was driving home p.o.'d about the emissions test failure and the dash lights went out. I havn't tried the dome light yet, but will get to it. I'll post up when I have it back together.