I have a spot light that plugs into my cigarette lighter and I need to replace the plug. How do I find out which wire is the ground since they are not marked?

jtrippy

 

If it is a incandescent then polarity does not matter, just plug the new one in and measure with a meter.
Max.

 

the automotive spot lights are likely LED-s
since LED-s may have low reverse breakdown voltage you may use 1A 1N4001-1N4007 or more powerful diode in series with your light - then at correct polarity it lights up and at reverse it won't - unless it has an internal "polarity don't care" rectifier - in which case there's obviously no difference

 

I have a spot light that plugs into my cigarette lighter and I need to replace the plug. How do I find out which wire is the ground since they are not marked?

jtrippy

the ground wire is the one that is connected to the connector that protrudes from the side of the plug

 

I have a spot light that plugs into my cigarette lighter and I need to replace the plug. How do I find out which wire is the ground since they are not marked?

jtrippy

Just rewire it the same way that it was wired on the original plug.