Check the alignment of the alignment marks of the housing and the cover of the air damper heater (A). If they are not aligned, loosen the pinch screws and rotate the cover.
With the coolant temperature below 10°C and the engine running at idle, check the operation of the air damper and overspeed cam by touching the air damper heater housing. The heater housing should warm up shortly after starting the engine. The air damper should open as the temperature of the machine rises. After the coolant has warmed up, the high idle switch should operate.
If the heater body does not heat up, then check the electrical element as follows. Disconnect the heater connector and check the wiring for continuity and resistance. The resistance of the thermocouple should be approximately 6 ohms at 20°C. If not, replace the automatic air damper heater assembly.