Since the Putco resistors have rather short wires (maybe 3in) it is strung up between where the wires & screws are. I put tie wraps around the wires connecting to the resisitor cause those don't get really hot at all, it's just the metal on the resistor that gets hot. I bought some engine shielding that can take high temperatures and put it around the resistor over the weekend, I'm pretty sure it will work fine for the long run.