I guess the idea is that a blown fuse or faulty wiring would never lead to the fan not working and thus the car overheating. This will be the wire that connects your switch to your fan power wire.
How Long Can A Car Battery Power 6 Types Of Fans Home
How to wire a house fan to a car battery. Get the 10 gauge wire and place it through the hole in your fire wall. Take the second jumper wire and connect one end of the jumper wire to the positive wire from the fan. Connect the negative input clamp black to the negative battery post on the automobile battery. Simple answer is this. Positive red terminal of the battery to the red wire of the fan negative black terminal of the battery to the black wire of the fan. Attach the red power inverter input clamp to the positive pos or battery post.
Connect the other end of that wire to the engine block or any metal part of the car body. Step 2 power inverters have one or more outlet plugs. Plug the fan into the power inverter. I wired my radiator fan directly to my battery on a suggestion from a reputable vw aircooled and diesel mechanic my dad takes his cars to. Attach the black power inverter input clamp to the negative neg or battery post. Connect the inverters positive input clamp red to the positive battery post on the automobile battery.
So now we have a wire that goes through the engine bay to the cabin of your car. But it seems that this just burns up the rad fan switch leading to the fan never coming on. If 12v then red to red and black to black or to the car body if the battery is connected to the car. Connect one end of the 12 gauge jumper wire to the black ground wire of the fan. It depends if it is a 12v fan or mains powered. Now take the power wire from your fan and connect it to the wire that is going through the firewall.
You may want to insert a switch in the red wire. If it is mains you will need an invertor. Turn the fan power switch to off.
















