Testing LED Trailer Lights Using an External 12 Volt Power Source

Updated 11/06/2012 | Published 11/04/2012

Question:

I got some lights that have 3 wires green,black an white. I wanted to test them and could not get them to work, can you just hook them to a hot wire and ground? can you tell me how to hook it up and test them?

asked by: Phil

Expert Reply:

You should be able to ground the white wire and apply 12 volt power to one of the other wires and get the light to illuminate. If the ground is not sufficient, the lights will not light up. If the power source is not putting out 12 volts or requires a certain amount of load before it will allow power through the lights might not work. The back of the light housing normally indicates the function of each wire.

One method you can try is to use a car battery, attach the ground wire to the negative post and use a circuit tester as a type of jumper from the positive post to the wire.

expert reply by: Michael H