Heater blower motor slow to start

Long shot: have you checked your cab air filter? If its all clogged up, like mine was, it can slow stuff down, burn it out early, etc.

Captain hindsight usually only helps one person at a time, but maybe its worth checking?

 

I don't know about your motor. Both of mine in this truck do have a resistor or something like it. It has Four wires hooked to it than goes to the motor. Not sure where the wires dome from. Same on my little truck and my blazer.
If you trace the wires from the motor back you will find the gizmo I'm talking about.
Good luck.

 

Turn fan on high for a few minutes,then feel the wiring,make sure it's not getting hot.
Check the blend door,make sure it's not stuck part way.
Check the ducting,make sure nothing is clogging it or holes etc.

 

What exactly do you mean by "the blower is slow to start"?? That is a blend door system. The blower motor has 4 wires, 2 big ones and 2 small wires. The big ones are the power and the ground. The 2 small ones are a blower signal (intended speed) and a feedback (actual speed). The FCU (front control unit) sends a signal to the blower motor based on the position you have the blower speed dial in and then the feedback wire sends a signal back to the FCU. Basically telling the FCU if the desired RPM of the motor was achieved. A slight lag time is normal especially say at key on, or if it was off, then you turn it on. The system has to have a little time to make sure everything happened as it was designed. Do you have any codes on the dash from 146? Give a bit more info and I may be able to help.