Turn signal light question

I have a pair of older motorcycle turn lamps that I want to use for signals on my 36.
When I tested them it appears that having the ground wire from the light to the ground post and hot wire for the light to the batt pos it won't work but when I switch them they do.
Are these light pos ground? And if so how would I use them.


They are the perfect size to fit behind the frame horn covers on the fender extensions.
Thanks

 

Modern electronic lights withcircuitry and LEDs care about polarity, but older resistance lamps are not positive or negative ground. The filament gets hot when current runs through it, direction does not matter, so polarity is not the issue.

They may be combo turn-signal & tail-lamp (running light) bulbs, with one wire for each, and the ground coming through the case. If you are using the old bulbs, they may have one of the filaments burned out.

You need to remove a bulb, and look at the bulb (or better, the socket) to see how many contacts there are. If you look carefully at the bulb, you can see the individual filaments.

Spend some time with a DVM or other continuity checker, and figure out where the wires connect. Polarity is not the issue.

 

You're right I had a bad connection and it does work both ways.
Thanks.