Behind the glove compartment on the dash.
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.
Your truck has both. the resistor is between the switch & blower.thje resistor controls the blower speed
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.
Behind the glovebox and it secured with only 2 screws.
Pull out the lock on the blower motor resistor wire harness connector to unlock the connector latch . Depress the latch on the blower motor resistor wire harness connector and disconnect the connector from the resistor. Remove the two screws that secure the blower motor resistor block to the HVAC housing. Remove the resistor block from the HVAC housing............
Blower motor is under the dash on the passenger side.
replace the blower motor switch
The resistor is under the passenger dash just left of the blower motor
The blower motor resistor is located under the hood, in the right hand cowl, behind the windshield washer bottle.............
To test the blower motor resistor, unplug the resistor connector. Each blower motor switch input terminal on the resistor must have continuity to the resistor output terminal, which is connected to the circuit going to the blower motor. If the blower motor resistor continuity does not check OK, replace the faulty resistor.You need a multimeter to test the resistor block and there should be continuity between all terminals.
I have been working on an issue with my 2002 Dodge Ram. The blower motor and resistor are both located on passenger side under the dash. Easily accessible in cab.
either the control head is bad or there is a blower motor resistor that is bad.