Electrical issue: interior dome light

[Thrasher]

Just picked up my '84 Carrera coupe on Saturday, and I'm trying to knock out all the little, "easy" stuff first while I'm still enjoying the car and before I tear into the more serious stuff that'll render it undrivable for a bit.

Anyway, one thing I thought was annoying was the interior dome lights were not working. Bought new bulbs, put them in and still, nothing (on either side).

So, I took out both lights and got the VOM out. With some playing around, determined that it used a chassis ground and two hot leads. Lights themselves seem to be making continuity ok, so I plugged everything back up and with some jiggling and improving the light assembly body to chassis ground connection, I have them both working in the ON position, but still nothing from the door switches (either one).

I've searched the archives and have studied the wiring diagram in the Haynes manual. As I understand things, the two wires (one is black, other is orange/brown) carry 12V, and the circuit can be completed by pressing the lens to one side (works fine) OR by the door switch grounding out when open.

But, I don't see any lead from the door switch to the light - how does this complete a circuit?

I plan to pull out the door switches and see that they're functional. The original owner had an "Ungo Box" aftermarket alarm installed and I know they use the door switches.

Any thoughts?

[kach22i]

Call me a sissy, but if I were you - STOP NOW.

I read many dome light threads, and a couple of guys regreted ever opening pandora's box. Some claimed to have major electrial bugs after trying to fix a simple problem.

I keep a small flash light in the door pocket and purchaed one of those key lights. Good luck.

[no substitute]

Don't know if this helps or not, but the rocker switch lights have three positions on my SC. On all the time, doors open or closed, off all the time, doors open or closed, and on when the door is opened, triggered off by shutting the door (button on hinge plate area is the switch for this third setting).

['89cab]

the switches in the door jam get oxidized and i've always had luck just unscrewing them (they're under a rubber cover) and hitting them (and the jam's threaded part) lightly with sand paper or wire brush. you could also use the electical lubricant (can't remember what it's called, but its worth having a small can) because the plastic part starts hanging up on the aluminum.

[Thrasher]

Originally posted by no substitute
Don't know if this helps or not, but the rocker switch lights have three positions on my SC. On all the time, doors open or closed, off all the time, doors open or closed, and on when the door is opened, triggered off by shutting the door (button on hinge plate area is the switch for this third setting).

Right, and my problem is the third (normal) position - both lights on when either door opens - doesn't work.

It's working fine in the "tilted" positions.

I just want to check the door switches, but I'm not going to go nuts on the wiring to solve this. Culprit is likely the aftermarket alarm (which like the Don Johnson carphone) is non-functional dead weight and will be removed.

[david914]

I just went through the same thing, only my dome lights wouldn't shut OFF. Had the Ungo box too. Turned out to be a combination of the Ungo box "Unworking" and a short behind the passenger side dome light. If you follow the diagrams in the Haynes manual, you'll find that the dome light wires from the door switches all come together on the passenger side right around the hood strut. I don't remember what color wires are there, but if you check your wiring diagrams, you'll be able to figure it out. There's a good chance that someone disconnected a connector because of the alarm. You just need to put it back the way it came from the factory.