Defroster motor

[KennyCuda]

I pulled the heater box out of my 1970 challenger 340 non ac car today to change the defroster more which wasn't working. I had it rebuilt and when I put it back in the motor isn't working and keeps blowing fuses. Do you think the motor is shorting out or could it be something else. Very aggravating for zero results after all that work.

 

[Adam]

There must be a way to check the motor with a multimeter. Don’t risk an under dash wiring harness fire.

 

[KennyCuda]

Im getting power from the switch to the plug of the resister that feeds the defrost motor I think the motor isn't right-- thought maybe someone might have an idea if it was something else

 

[Challenger RTA]

Connect the motor to the battery directly see if it works. You can use a household light switch to control the power.

 

[Challenger RTA]

Im getting power from the switch to the plug of the resister that feeds the defrost motor I think the motor isn't right-- thought maybe someone might have an idea if it was something else

I understand that. It's a process of elimination. Funny thing It doesn't work now and it didn't work before? Check it.
By applying a different power source you then know what it is or is not.

 

[Xcudame]

Is the resistor for the motor OK? I remember going through about 3 or 4 resistors years ago for my 70 Challenger before I got one that would work! For awhile I had the defrost motor hooked directly to battery with an inline fuse. Man did that motor blow some air. Unfortunately I didn't like how much current it drew especially at idle (big time discharge with it running and the headlights on). So finally got a good resistor.

 

[KennyCuda]

I pulled the motor out and hooked 12 volts and a ground to the motor right from the batter and it did nothing so I sent it back to the guy to re-do now gotta wait for it to get back