Targa Dome Light Stays On

[arbita1]

I just replaced the dome light in my targa as the old one was broken.

In the foward position the light is supposed to go on and off based on the door position. However mine is staying on regardless of whether the doors are open or closed.

I pulled out both door contact switches and they are connected and look fine. However when I press the button and break the ground the light doesn't shut off.

The car does have a nonworking aftermarket alarm which I haven't completely removed yet. Could that have anything to do with it? Where does the door contact switch wiring meet up?

[schoward]

I think that is correct.

In my 81....

1. Light tilted/pivoted toward front of car = On at all times (eg map reading); Doors have no effect.

2. Light 'centered' = Off at all times

3. Light Tilted toward/pivoted toward back seat = On only when doors open

Check your owners manual for correct operation, but my 81 operates that way which is line with my owner's manual.

I opened mine up once and I believe it works like this...assume the light always has power then....

In Mode 1 above, light uses the ground wire in the targa bar activated by pivoting the light toward front of car -> light goes on and stays on

In Mode 2 (center), no ground so no light - ever.

In mode 3 (pivot toward back of car) - it uses ground provided by either door's door switch. On mine I once had problem where pass door would turn it on while Driver's side did not. Cleaned the door switch (ground connection) and it fixed it.

[arbita1]

I had checked my Owner's manual and I tried both positions. The light stays on with no effect from the doors in the tilted forward and rear positions. It does turn off in the center position.

[schoward]

If staying on when pivoted to back of car, it is finding a ground somewhere - perhaps in the wires which run to the doors. They can create a ground if they get chafed, etc against the body. I would gently remove the door switches to see if the grounds are still connected. It is not uncommon for them to break off, fall in the fender and create a constant ground by resting on the metal. I suppose a test of this could also be if your 'door open' buzzer is intact and working. If it is, that kind of rules out the above. Many folks do remove those buzzers though so may be necessary to physically check the wires.

If you remove the whole assembly (i think it pops out), you should see the ground wire for Mode 1 (front) right above the light assembly (it is grounded right to the targa bar above the light with a little slip-on fitting). You should also find the ground wires for Mode 3 which end up at the doors. By disconnecting one or the other, you may be able to narrow things down.

Good luck.

[s_chev]

I had that same issue and even after replacing the light fixture, it still stayed on. It turns out that the common ground wire on the fixture is close enough to the top of the targa housing that it touched and grounded the light completing the circuit. I pulled the light fixture back out and put electrical tape over all the wires and it works fine now. The clearance is very close up in there.

[4flyboy]

Originally Posted by s_chev

I had that same issue and even after replacing the light fixture, it still stayed on. It turns out that the common ground wire on the fixture is close enough to the top of the targa housing that it touched and grounded the light completing the circuit. I pulled the light fixture back out and put electrical tape over all the wires and it works fine now. The clearance is very close up in there.

Ditto had the same problem and fix on my '74 Carrera Targa.

Scott

[arbita1]

Originally Posted by s_chev

I had that same issue and even after replacing the light fixture, it still stayed on. It turns out that the common ground wire on the fixture is close enough to the top of the targa housing that it touched and grounded the light completing the circuit. I pulled the light fixture back out and put electrical tape over all the wires and it works fine now. The clearance is very close up in there.

Hopefully that's it. I'll try that tonight.

[relayswitcher]

Not everyone but some forget there is courtesy light just under the dash over the glove box that can be left on or off when the door closes position, wouldn't hurt to check... especially if you are getting a dead battery and don't know why. This light works in my Targa.... I've never noticed if there is one in the coupes. Relayswitcher / josh

[arbita1]

Originally Posted by s_chev

I had that same issue and even after replacing the light fixture, it still stayed on. It turns out that the common ground wire on the fixture is close enough to the top of the targa housing that it touched and grounded the light completing the circuit. I pulled the light fixture back out and put electrical tape over all the wires and it works fine now. The clearance is very close up in there.

That was it! I put electrical tape over the ground connection to the top of the targa bar and it works as it should.

Sometimes it's the small wins that make you feel good. Thanks a lot!

[relayswitcher]

Glad to hear you found it. It really is the small wins that seem sweet. R.

[Shadetree930]

God bless teh intarwebz and PP BBS

[arbita1]

Just to update this old thread...

I had followed the instructions above and put electrical tape on the connections of the light and that had resolved my problem...well, temporarily. The light started to come on by itself again and I would find it on (for who knows how long). I left it shut off and figured I'd deal with it another time.

So the other day I started to look into this. It turns out there were two very small tears in the vinyl ceiling at each side of the light. This exposed a small amount of metal which was enough to touch the light bulb connection on each side of the fixture and ground it (keeping it on regardless of door position). I put electrical tape over the spots on the ceiling and the problem was solved.

Just something else to look for if you are having this problem.