Some carb cleaners are pretty nasty on some plastics, (don't leave your Craftsman screwdrivers sitting in the stuff!) but I have not seen it adversely affect wiring. I guess it could if the wire coating was the "wrong" material.
Carb cleaner will eat plastics that arn't designed to be fuel resistant and can melt paint. Depends what the insulation is made of , as long as you don't get it on anything else you can use it to clean the wires.