[stangmon97]

I just converted my buick over to 12 volts and no one can seem to give me any advice on this ballast resistor I bought. I called the company I bought the parts from and they only told me where to put it, they had no advice on what it actually was.

so what is is this thing?

do I have to put it in?
and what happens if I dont?

thankss guyss