Diagram for location of blower motor resistor can be found here
http://autorepair.about.com/library/images/bl441a-lib.htm
For the 1989 Dodge Ram, the heater blower motor resistor can be found on the passenger's side, on the bottom of the heater box. It is beside the blower motor.
Replace heater motor resistor.
check the blower motor resistor pack. should be firewall side of heater rectangular connector with 4 or 5 wires.
Inside the cab. Passenger side. Inspect the heater ducts Look for five wires going to the resistor. Should be two screws holding it in.
in the dash but check the resistor 1st the blow e.z. it is in engin comp. passinger side on heater core lines it looks just like a water heater fuse
The resistor block or blower motor resistor is used to control the speed of the blower motor. That is how you get the lower speeds on your air conditioning or heater. The higher the resistance the lower the speed of the motor.
I have changed resistor a d blower motor still not working, maybe i missed a fuse or could the control switch not work?
Under the dash, far passenger side.
Blower motor resistor assembly is located under dash board on passenger side.
RIGHT BESIDE THE BLOWER MOTOR UNDER PASSENGER SIDE OF DASH
The Blower resistor should be tested which is located near the blower motor, the resistor is probably faulty.
The blower motor resistor pack is bad.