We've had the Airstream for several years and have never bothered using the range hood extraction fan that is incorporated in the Sharp microwave convection oven - because is was way too noisy and didn't seem to do the job it was supposed to do. Also the external flap on the exhaust vent banged around in the wind all night so I closed it using the tabs provided.
Recently thought to find out why it worked so poorly and released the flap on the outside vent and turned it on. Much noise and not much suck and I noticed the outside flap was being sucked hard back towards the duct instead of swinging outward - which only explains the lack of suck inside if the fan is running in reverse.
Anyone had cause to check out the circuitry - is the fan and light supplied from the 12V
house system and is the fan controlled by a relay operated via the microwave electronics, and if so, could the fan be running backwards because the 12V
supply is connected back the front.
Failing that, anybody removed the microwave and if so, any pointers on how it is fixed in. As in many things, the Airstream owners folder is rather ambiguous and has several possibilities, none of which make much sense at first reading