How to Wire a Cooling Fan to Your Car (DIY Electric): 9 Steps The Equipment. Here is only some of the equipment we need to have in order to make this Saftey. One main safety step is to unhook the BLACK (negative) wire from the battery, and when The Setup. Above is the picture for our wiring plan!Wiring (first Part) Get the wire situated and know which wire is ground and which wire is power! For See all full list on instructables How To Properly Wire Electric Cooling Fans A larger radiator, a larger clutch-fan, and a shroud would probably keep your engine cool; mechanical fans can sometimes work better than electric fans. For some, however, electric cooling fans are not only keeping the engine cooler in traffic, but they keep the engine cool at stop lights, too.