1960 Biarritz question

[Whit]

For electronic geniuses out there. The bulb for the door warning lamp (#90) has two contacts. I thought one was for ground and one for hot wire. When I measure the current on the socket, both sides are hot. Do I have wires crossed somewhere. I thought the bulb case would pick up ground, which it does on the battery test. I assumes that the bulb socket was the ground. Both wires going to the contacts can't be hot...what gives here?

Thanks   Whit

[David Greenburg]

My recollection is that both are hot; activating the switch creates ground.

[Whit]

I'm curious David, why would both ends of a filament be hot? Doesn't the #90 bulb only have one filament, or has one gone away?

Whit

[76eldo]

Where is this bulb located?
If it's in the door it needs two contacts on the bulb since the socket is not grounded to anything.
If it's a one filament bulb with two contacts the wiring takes one side to hot and one side to ground. The harness connects to the pin switches in the jambs and makes the ground when the door is opened.

This is different than a tail light bulb that gets snapped into a metal tail light housing which is bolted to the body and automatically grounded.

Brian

[Whit]

Thanks Brian...I'll check it out tomorrow.

Whit