Electrical problem

[67gt]

I think that I have a short somewhere. My left and right courtesy lights do not work. It is very weird; when I test the bulb holder, it says 12volts. I know the bulbs are good and it does not light my tester light either. Also now if I leave the car overnight my battery dies . I have spent a long time looking for the problem. I took out my glove box and all the gauges but I still cannot find anything out of the ordinary . Do you guys have any tips on how to find the problem. Everything else seems to be working fine.

Thanks

 

[notny41]

Try replacing the turn signal switch. Checker and AutoZone have replacement cam's for about $10 in their STOP section.

Also would suspect the light switch.

Those switches run a LOT of crap. And the light switch has power weather the key is on or not....

You should be able to find a wiring diagram on this site somewhere I would think.

 

[iskwezm]

when you check the sockets for power are you using a test light?Are you using a different ground then the socket? Is the headlight doimmer switch left on?

 

[limey66]

Sounds like you could have a high resistance in the circuit somewhere - you'll see 12 volts with a meter, but put any load on it (like the lamp or your test lamp) and the volts will drop like a stone. I'd suspect one of the door switches, could not be shutting off properly draining the battery through the courtesy light circuit, but at such a high resistance it doesn't make the lamps light. Pull 'em out and short the contacts together - if the lamp lights then that's your problem.

Another less likely option (seeing as the whole courtesy lamp circuit is 'out') would be that the lamp is not making proper contact with the holder - is the spring OK in the back of the lampholder?

 

[67gt]

notny41: my turn signal lights work.
iskwezm: I have tested the sockets with both a volt meter and a test light. the meter tells me 12 volts but the test light will not light.
limey66: I looked at the swiches too. They looked good but i will look again.

Also my golve box light does work and that is on the same circuit right?

Also what would be considered high resistance? what would be the best way to test with an ohem meter?

Does anyone have any diagrams that would be helpful my book isnt helping me.


Thank you

 

[notny41]

This might help:

(Found it in another thread)

http://www.geocities.com/midlife66/wiring/wiring.html

I wasn't able to pull up the TIFF files. Hope you have better luck than me. I do have jpg's of the 65 diagram but don't know how close they are.

P

 

[limey66]

Also my golve box light does work and that is on the same circuit right?

Also what would be considered high resistance? what would be the best way to test with an ohem meter?

Yup, the glove box light is on the same circuit. If you could measure the resistance between the lampholder and the battery (disconnect the battery first) it should ideally be no more than a couple of Ohms at the most, anything more and you got a problem.

Just a thought - when you measured your voltage at the lampholder where did you ground your other test lead? You may have a faulty ground that means you have 12V at the terminal, but it can't flow to ground. The flat battery could be a co-incidence.

 

[notny41]

Whoops - just re-read the original post. When you said courtesy lights I thought that meant the signals. I was thinking those were the same as the blinkers on 67. My bad.

 

[67gt]

I have tested my switches and they are both good. I think that I have narrowed down the problem. I am testing the wires that go to the switches and the power wire still tells me 12 volts. However, it has a very high resistance when tested to a good ground. The ground wire has a “normal” amount of resistance (based upon testing other circuits that work); also tested with the same ground. How would I resolve my problem? I am not sure what I am looking for now. Any help would be great.

Thank you

 

[krash kendall]

I had the same problem. Meter showed 12V but no sparkle, sparkle. Figured bad ground but turned out to be corrosion at the fuse. Pop it out and back in and see what happens. If the switches are bad (my glove box light switch had an internal short - I removed it) you will kill your battery.

 

[67gt]

Is the courtesy light fuse is the vertical one all the way to the right?

 

[krash kendall]

I believe it says "dome"

 

[Tim65GT]

Check the light switch. Two black-blue wires from the same terminal feed the left and right side Courtesy light circuits separately. You should be experiencing problems also with the console light circuit, the roof console map lights and rear pillar lights. (if you have these)

 

[67gt]

Thank you all for your help. I think that my problem is in the light switch. when I bypass the switch the lights work. I will pull it out tomorrow and test it.

 

[limey66]

Yeah, what they said...

The fault might go all the back to the battery, but if you've only got the problem on one circuit, it's probably at the fuse.

Good luck.

 

[notny41]

hmmmm


...

 

[1966conv]

When using the test light, what are you grounding against. In my 66, the courtesy lights use the metal dash as the ground. When I restored I painted "everything" and they didn't work either. Then I moved the nut/bolt around wore off a little paint and got a ground again.