I have one marker light that does not work. I could not get power to the fixture so I pulled the connector out and found one wire was not crimped down enough to hold the wire in. I removed the wire from the connector and then put a volt meter to the black and white wires. I don't get a reading. My question is, are the two wires hot? or is one a negative and the other a positive. Most RV's just use one wire for hot and the ground is the RV. Appreciate any advice on 12 volt
power to the fixture.