So i recently discovered that the meathead buddy of mine that installed a stereo for me did a bad job. Instead of running a wire to the fuse block or wherever it should go he just found a random wire (which happaned to go to the switch for the radiator fan) and wired it in there. The result was a smoking melted up mess under my dash. So now the radiator fan doesnt work at all making my 400 small block heat up real quick and the radio doesnt work either.

So can somebody tell me what guage of wire I should use for the radiator fan and where should I hook it up? Straight to the battery or into the fuseblock or what?

 

dont have a book, but how I wire mine up was I ran an 18 gauge from the battery to the fan motor, then 14 gauge ground from fan motor to a standard bosch relay and 14 gauge from temp sensor to relay and grounds on the relay. Factory I believe was power running through a heavy duty relay, but I find it better running grounds through them. Hope this helped a bit.

 

Do NOT use an 18-gauge wire, that's way too thin for the fan! 18-gauge is for door bells, not for high-current loads.

You should be using 10-gauge wire to power the fan. The best would be to do so through a relay (to minimize the run or the thick wire and minimize the voltage drop).
Use a 20A-30A fuse and if you use a relay, just search and you'll find a lot of links on how to wire one up.

You may use an 18-gauge wire to control the relay, btw, that wire wouldn't conduct much current.

Lou

 

yes you are right my mistake I meant 10 gauge

 

great! thanks i got it all fixed back up now and its working great