Heater??

[FJ157]

Could there be something in my heating electrical causing and over voltage to my blower motor?

here is the long version

Heater motor stopped working (filled the cab with smoke) so i replaced the resistor (was definitely bad), worked for 30 seconds more smoke and the relay popped. So i ordered another blower motor, got it in and it was a 12 v not 24, got annoyed and thought i would see if i could just fix what was burnt up in the old motor. Tore it down cleaned up contacts cleaned out 30 years of gunk put it back together and plugged it in. 15 seconds or so of glory with all the 5 fan speeds and all then smoke and relay pop. So i got another blower motor from Coldtaco since he had one laying around. And before i pop it in and turn it on is there something else i should look at? I would hate to burn up my replacement fan my not checking for something else?

 

[Josh NZ]

Excessive resistance or jamming/friction in the motor can cause heat in large quantities, and can melt wires. Is the actual blower motor smoking? I know that the speeds are just different amounts of resistance.

If you have a multimeter then check the resistance in the cables using the correct formula. You can rule out a bad wiring circuit by just running some small lengths of cable straight to a battery off the blower motor. Maybe try it with the smoky motor before you plug the good one in.

It sounds to me like the motor has an internal fault and needs replacing anyway.

If your wires are over volted I can’t imagine it would be isolated to just the heater wiring circuit and you would probably see other components failing too.

 

[FJ157]

Excessive resistance or jamming/friction in the motor can cause heat in large quantities, and can melt wires. Is the actual blower motor smoking? I know that the speeds are just different amounts of resistance.

If you have a multimeter then check the resistance in the cables using the correct formula. You can rule out a bad wiring circuit by just running some small lengths of cable straight to a battery off the blower motor. Maybe try it with the smoky motor before you plug the good one in.

It sounds to me like the motor has an internal fault and needs replacing anyway.

If your wires are over volted I can’t imagine it would be isolated to just the heater wiring circuit and you would probably see other components failing too.

(yes the motor was the "smoking gun") i agree but when i took the motor apart i quickly realized there are no real components, its basically an alternator. there were no circuits just coils a magnet and a spring loaded stator or brush what ever you want to call it. one side was more worn than the other but after i sanded down all the surfaces it looked gtg. I was actually pretty convinced that it was going to work for a while. It was not the case. I am going to double check the voltage before i plug the newer motor in but i was hoping some one could say....." oh check the flux capaciter behind canooter valve for an 18 degree rotation against the fluffinator for proper synchromeshment"