Fuel Heater: Description and Operation

Fig.18 Fuel Heater Location:

The fuel heater assembly is located on the side of the fuel filter housing (Fig. 18).

The heater/element assembly is equipped with a temperature sensor (thermostat) that senses fuel temperature. This sensor is attached to the fuel heater/element assembly.

The fuel heater is used to prevent diesel fuel from waxing during cold weather operation.

When the temperature is below 45 ± 8 degrees F, the temperature sensor allows current to flow to the heater element warming the fuel. When the temperature is above 75 ± 8 degrees F, the sensor stops current flow to the heater element.

Battery voltage to operate the fuel heater element is supplied from the ignition switch and through the fuel heater relay. Also refer to Fuel Heater Relay.

The fuel heater element and fuel heater relay are not computer controlled.

The heater element operates on 12 volts, 300 watts at 0 degrees F.