The heat modulator in the 1998 Ford Ranger controls the thermostat, blower motor and temperature of the truck. A defective heat modulator prevents the heat from being adjusted inside the cab of the Ranger. Certain signs show up during the operation of the heater unit when the heat modulator is defective.
Ford has issued 13 recall notices on the 1998 Ford Ranger. One recall deals with a heater problem that some Ranger owners have experienced. This recall involves the electrical wire that runs to the heater module. The wire connection, which goes to one of the elements, has a crimp in the connection, causing the heater modulator not to work the Ranger's heating system. The wire, connection and element need to be replaced in order to correct this defective heater modulator problem.
The controls of the heating system can get stuck so that even though the operator can turn the controls, the heating system stays in the same position. This condition is a strong indication that the heater modulator is defective in the 1998 Ford Ranger. The heater modulator is not operating the thermostat controls because the modulator is getting stuck in one position and the heater inside the cab continues to blow heat. The heater modulator must be replaced before the blower and elements burn out.
Another sign that the heater modulator is defective on the 1998 Ford Ranger is when the blower works but no heat is blowing through the vents of the truck. The heater modulator is not signaling the thermostat that the heat needs to be adjusted. The heater modulator controls the adjustment of the thermostat, but, because of the defect, it fails to communicate with the thermostat. This defect can cause the thermostat and blower to burn up, because either the wiring connections are loose or the transformer is failing. The Ranger owner must take the vehicle in to the dealership to have the modulator replaced before major damage is done to the thermostat and blower motor.
