6. Trouble shootingMalfunctionCauseCheckVentilator and heater do not workVentilator does not workVentilator does not workHeater does not workPower failureCheck 12 VDC and/or mains voltageMechanical obstructionClean filter and/or remove obstructionElectrical failureCheck fan impedance ~30 ΩResistor defectiveMeasure power resistors:Specifications: 15 Watt and 50 / 39 Ω23