Help With Wiring
 

I'm installing a pair of NiLight 18W LED spot lights on my 2010 Prius, which has fog lights. I want to disconnect the fog lights, and use those wires to run the spot lights. My spot lights have red and black wires. What color wire from the original fog light wires should I hook the red to, and what color wire from the original fog light wires should I hook the black to, so that I can turn them on with the original dash mounted fog light switch?

Normally red is going to be the 12 volt line(hot) and black will be ground. If you can't tell by just looking at the wires going to the fog lights which is hot, then either get a meter or a cheap automotive circuit tester to determine the hot line.
JJ

According to this, it will either work or it won't. :thumbup:

Thanks. I just found my old battery tester. I guess the colors on the LED are the same as the colors on battery cables, red for negative.

You mean black? Every car I've owned, domestic or foreign, the positive battery cable is red.

Some times body lights use pulsed DC and LEDs don't like it.
The pulsed DC let's the computer know when a light has burned out.

Thank you. I thought Black was ground. Good thing I talked to you.

Fortunately, the 3rd-gen Prius doesn't. OP should be okay swapping the lights.

Thanks to everyone.:)