W900 Blower motor in cab

i just replaced a blower motor on a companie w900 and took me about 30 mins but this was on a day cab so it might be diff on a sleeper

 

I had to take the panel off under the glove box

 

When I get one having an issue like yours I first check the amp draw and voltage at the motor with the engine running. A good motor with a good B+ and B- circuit will pull 16 amps on high speed. If the amp draw is higher than 16 amps this indicates a weak point in either the B+ or B- circuit or the motor bearings are lacking lubrication. Also inspect your blower circuit breaker terminals and wire connections and replace the 30 amp breaker. You can also measure amp draw and voltage on the out going side of the breaker and compare that to your readings at the motor. This will help you establish if the circuits are healthy or not and if you need a new motor to correct the problem. A poor B+ or B- circuit will cause voltage drop and high amp draw from the motor.

 

Yeah, it most likely needs a motor, but it wouldn't hurt to spend a little time checking things out to make sure that new motor isn't set up for premature failure due to a poor connection causing a voltage drop. I've seen guys replace their blower motor twice a year and just call them defective motors to later find a burned/loose/corroded connection causing all the motors to fail, but it's your truck your call.

 

if your motor really is bad (check it's running AND start up amps) it may have taken out the harness again if it was bad before.