I have a 1990 Pontiac Transport SE, I have the changed the motor on the driver's window which is power...take off the door panel and you will see the motor...not too difficult of a job...follow the old motor route...
Transmission control unit for a 1990 Pontiac transport?
If you have checked and the blower motor has both power and ground then the motor is bad.........
Do what?
Inside the blower motor housing directly behind the electrical coupler.
In the truck!
To replace the heater blower motor: First unplug the wire connectors. Then remove the screws and the motor will pull out. Reverse the process to reinstall the blower motor.
i had a 1990 acura legend my blower motor was located under the passenger side dash board
If you are saying that the blower motor only works on the high speed setting, then the Blower Motor Resistor is defective and needs replacing.
Underneath the wiper motor assy.
Check at the blower motor itself. Have it turned on and tap the end of the blower motor with a hammer. I did this and found out that the blower motor was going out. The blower motor is on the top passenger side under the hood. Also check the wire connections. Make sure they are seated good. If this includes for the heater then I would say the blower motor is bad.
Disconnect battery ground cable. Disconnect blower motor electrical connections. Remove blower motor attaching screws, then blower motor. On models with A/C it may be necessary to dismount alternator and move away from module. Reverse procedure to install.