Parking light conundrum

[Fairlane514]

1946 Super Deluxe...

Bought the car recently and it had aftermarket wiring and turn signal system.

I removed all the wiring because it was done poorly and cheaply.

I bought new original style harnesses and removed the turn signal system.
The PO installed dual contact front parking light sockets and used Sylvania 90 bulbs. These bulbs are dual contact single element.

My problem.....I have power to one of the contacts in the socket and ground to the socket housing. The bulb does not light up (new bulbs).

I jumped power to both contacts in the housing and still no light up.

I removed the bulb and went straight to a battery with test leads and no light up. I also tried powering both contacts on the bottom of the bulb at the same time.....nothing.

I have 4 different bulbs all act the same. I have a 1158 dual contact dual element bulb and it will light up one element when installed in the socket.

The alignment pins on the socket and the sylvania 90 are in the same line 180 from each other, no offset.

I could just buy a single contact socket and change it out, but Im curious about this issue.

The Sylvania 90 did light up when used in the turn signal system, but I dont remember if it lit up in the "parking" position.

Again its a dual contact single element bulb .......weird

[Als48]

You will need to ground the brass casing of the bulb and apply power to the terminals to test your bulbs. I don't know of a dual element bulb without the offset alignment pins, but there must be some purpose for them.

[Fairlane514]

Yes, I grounded it......no light up....weird.....other bulbs light with same test....

[koates]

A bulb which has a single filament and two contacts on the base requires one base contact to be grounded and the other base contact to have power. The bulb base housing is NOT CONNECTED to anything. These configuration bulbs are not used these days except maybe for a dome light. Regards, Kevin,

[Fairlane514]

Thanks Kevin,

I will try grounding one of the socket contacts.

[Terry,OH]

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The 90 bulb is a 12V light. What is your battery voltage?

[Fairlane514]

Its been converted to 12v

Kevin was right, I grounded one of the socket contacts and it lit up