The Stovebolt Site Forums The Shop Area The Electrical Bay Heater fuse blowing

After going through the summer and part of the fall with no heater fan I finally broke down and replaced the one I messed up. The problem now is when I put the fan switch on full blow the fuse blows! I disconnected the fan and while checking the wiring at the final connector, (where the 3 wires from the fan switch plug into the (not exactly sure what it is)that is on the metal air box from the heater assembly where one wire goes to the fan) the fuse blew only when I put it on full blow. The fan works fine in the other 2 settings.
I figure there must be some sort of short where the contacts meet in the switch. It's not easy to remove the switch and I doubt there is anything I could really fix in there.
Any suggestions?

the connector on the heat duct is the "heater resistor", the switch runs the current for the motor through this to drop the motor voltage to provide low and med fan speeds, hi speed is full voltage directly to the motor. if low and med speed work ok the resistor and it's wiring must be ok. Be sure it has the right rating of fuse, hi speed will be maximum current, if the fuse is rated too low it could blow it. if thats ok, try to take a jumper wire from the heater wiring(before the switch) directly to the motor and see if it blows the fuse, if it does the motor must be the problem, if it doesn't the switch or hi-speed wire must be shorting out,then use a jumper on the heater switch from the supply terminal to the high speed terminal, if it still shorts out it must be the wire, if it doesn't it's probably the switch. hope this helps.

Thanks for the info. The fuse box says to use a 10a and I've blown a 15. The fan worked for a short time on hi, could blow dry your hair with it, then it started blowing fuses.
I'll try the jumper route to see if the fan is drwing too much current. I highly suspect the switch as it was 'touchy' in the hi position in the past. I am really regretting the day I started messign with the original motor, as it was actually working.

thanks again

You might also check to be sure you have a 12 volt motor, they look the same as a 6 volt and I know it sounds stupid but it happens once in a while...aside from that check the amp draw and voltage when the motor is on high setting. If you can blow dry you hair on high, that might be a clue the motor was misboxed. Some of the new generation of parts guys figure if it is old it must be 6 volt. Randy