Ford Workshop Service and Repair Manuals

Vehicles with diesel engines for the Scandinavian market are equipped with a fuel-fired booster heater, as because of the low ambient temperatures and the high efficiency of the engine there is not enough waste heat from the engine to operate the heating efficiently.

As a result, the booster heater increases the coolant temperature to allow the air passing through the heat exchanger to be heated up sufficiently.

The booster heater has a maximum power of 5 kW and a minimum power of 2,2 kW.

A fuel pump attached to the booster heater pumps diesel fuel from the fuel supply pipe into the pre-combustion chamber.

An additional pressure control valve is installed upstream of the fuel pump to reduce the fuel pressure to below 0,2 bar.

The exhaust gases are released to the outside via a separate exhaust system.

The smoke which develops when the booster heater is first switched on is normal and results from the nature of the combustion process.

The booster heater is automatically activated after the engine has been started (signal D+ from the alternator is active) if the ambient temperature is below 5 °C and the coolant temperature is below 75 °C. The coolant temperature is controlled by the system whenever the vehicle is being driven.

The system is not automatically activated if the coolant temperature reaches 85 °C, or in the event of malfunctions.

The system is switched off under the following conditions:

• if no ignition takes place after a second ignition attempt (following a pause of 90 seconds)

• if the flame goes out during operation and a second ignition attempt fails

• if the overheating sensor is triggered due to overheating

• the voltage goes over/under the specified value, or if the power supply to the glow plug or metering pump is interrupted

• the fan wheel is blocked or inoperative.

Section drawing of booster heater