Polarity on Factory Fogs?

I have a '00 XLS 4x4. I didn't like the look of the plastic inserts where the fogs are supposed to be. I purchased some factory fogs off of ebay. Does anyone know the polarity of the factory plug coming off the light? I can purchase the partial wiring harness from Ford for about another $40. They would plug directly into the fogs, but I still wouldn't know the polarity of those wires. help is greatly appreciated. The fog lights are installed, and look perfect. They just do not have any "juice".

 

[Bill Kemp]

You need an electrical test light. They are only a couple of bucks. Looks like an ice pick with a light in the handle and a wire comming out of the handle. Just clip the wire to a ground and touch the pick end to the wires and see which one lights it up. That will be your "hot" wire.

 

[kkreit01]

Thanks for the info, but will that method work directly on the bulbs? Don't you already have to have power in order for the electrical test light to function? I do not have any power to the fogs, nor the factory wiring harness.