So picked up a 91 ex sedan and heater motor didnt work. Fuse is good. So i replaced the resistor because it was fried. Then got a heater motor, replaced that and it didnt work. hot wired to make sure it works and it did.

Checked the fuse socket under the dash to make sure i was getting power, and is was. I probed the heater motor in multiple spots and nothing at all.

Can i just re wire the heater motor by itself or what? Whats the easiest path to go?

 

At the plug that connects to the fan motor,
You should have power and ground both present..

Chances are that the ground has burned up under the dash..
try tracing the ground wire to the point under the dash in which it was grounded and
look for a break in the connection between the two..

 

Did you use a multimeter?

Sometimes the circuit will test as good without load, and once the motor is on it doesn't function at all. Run a temporary ground to the battery (-) and attempt to run the motor using the 12V that it should be getting.

9/10 times, given the cold, the ignition switch is to blame as the contact carbons out. I had a similar problem on 3 different 89-90 civics where if you rotate the ignition slightly back, the blower turns on only to cut off seconds later.