Auxiliary heater does not switch on, automatically switches off, or motor does not run.

Symptoms

["If insufficient fuel, fill up the fuel tank. Start up heater two times, until the fuel lines are filled.", "Check if fuel level is above 4 US gal (15 l).", "Check fuses in the fuse box.", "Check if battery voltage is above 10 volts.", "If heater motor does not run, check battery voltage and fuses. If these are okay, the heater motor may be damaged.", "If the heater has been locked-out after three successive failed start attempts, it must be reset by an authorized Sprinter Dealer."]