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chetos · 11-05-2012, 07:14 PM

I'm getting 12 volts when the switch is on and 6 volts when it is off. Any theories on why I'm getting 6 volts. Kind of wanted to resolve this before I install the new led light I just bought.

idroba · 11-05-2012, 07:57 PM

That can be a difficult question but my stab at it is that the switch itself is dirty and with the sensitive digital voltmeters we have today, you are reading the flow through the dirt. Honest.

Are you dealing with the round white flood light or the light in the hood over the door?

chetos · 11-06-2012, 06:12 AM

Quote:

Originally Posted by idroba

That can be a difficult question but my stab at it is that the switch itself is dirty and with the sensitive digital voltmeters we have today, you are reading the flow through the dirt. Honest.

Are you dealing with the round white flood light or the light in the hood over the door?

Its the light in the hood directly over the door. I took the switch out to trouble shoot it so it's not a varible. It was corroded up so that was the first problem. I also cut out the socket, which was corroded up too, so that was the second problem. These things come in three! this last one is confusing. I can't tell where the ground wire goes so I'm not sure what is going on there.

dhtullos · 11-06-2012, 06:26 AM

My 1972 Overlander is the same way (6vdc), and I never could figure out why. I need to spend the time looking in to it, but fixing leaks and plumbing has been a priority. The schematic shows a just ground and +12v wire. I hooked up a LED replace light kit to it and it works fine. I thinks there is an open ground somewhere on the trailer and that why it will show up. If you are worried about it hook your trailer up to an electrical outlet with a known bonded ground. Measure from your bonded ground with AC and DC ranges. If you have show any AC voltage present on your 12vdc negitive ground or chasis, you have and open ground, miswired AC outlet, miswired appliance, or a defective device. Also check the lamp on your polarity indicator and make sure it works.

chetos · 11-06-2012, 06:09 PM

very interesting! maybe it has something to do when a wire is grounded to the alluminum shell vs the steel frame??? I'll put a cheaper test bulb on it before i pull the trigger on the new led light. thanks for sharing your story.

idroba · 11-06-2012, 07:05 PM

Quote:

Originally Posted by chetos

Its the light in the hood directly over the door. I took the switch out to trouble shoot it so it's not a varible. It was corroded up so that was the first problem. I also cut out the socket, which was corroded up too, so that was the second problem. These things come in three! this last one is confusing. I can't tell where the ground wire goes so I'm not sure what is going on there.

Some of the over the door lights had 12 volts going to them, and used a two contact bulb, with the second wire being run to the switch which was then grounded. So, the switch was in the ground line, not the hot line. A couple of the 60's AS that I had used that system. Yours could also be one of them.

If there are two wires from the socket and there is always 12 volts to ground at one of them, you probably have that "switch in the ground line" system.

That switch in ground line system was also common on cars where the door switch for the dome light actually completed the ground circuit. That way either front door (or rear door) could operate the light by grounding it and the +12 volts only had to go to the light itself, not to all the switches.

All the recent AS products I have had used the switch in the + line, like you would expect, but not the older ones.

garry · 11-06-2012, 07:50 PM

The wire going "to" one side of the switch has 12V the wire "from" the switch to the bulb has 6V when disconnected from the switch?

That is an indication of finding ground through another source something like the fan over the range or ??

You could run a new ground from the socket to the skin at some point and take care of the problem.