I was out messing around with my fan the other day. I have it wired to a switch and it keeps burning them up so I figured I would see what I could do to make it have less amperage going through it and in the process I wired it to an accesory fuse that wasnt in use. It worked great untill I tried to turn the car off. I think it was backfeeding through the ignition switch because it kept running untill the fan stopped spinning.

 

lol

That is pretty funn when you find those little quarks.

 

I think what was going on was that the fan was actually creating a current and backfeeding through the circuit to the ignition. The little current it created was enough to keep it running though , I was kind of surprised at it though.

 

You provided a second voltage source for the ignition. The internal motor windings are very low resistance. I would have loved to have scoped the voltage, can you just imagine all the noise those brushes generated on the 12 volt line. Amazing

 

Can you start the car by cranking over the fan?? lol

 

thats funny, but i am sure if it happened to myself i would not be laughing...

sounds like you should hook the fan up by just grounding the relay... so you dont have to worry about using fuses/ high output switch..

 

I did the same thing several years ago. Just get a relay and it won't happen anymore.