Lancia Trevi Heater Controls
Black fabric pipe from reservoir tank to T - piece at left hand side of heater
Green pipe from T - piece to valve that is controlled by the hot/cold mechanism. This is the vacuum feed.
Black fabric pipe from valve goes to the water valve in the heater pipe in engine bay.
Green pipe from T - piece to main control valve assembly via 7 way tube. This is the vacuum source for the main controls.
Yellow pipe from 7 way tube goes to actuator for hot/cold. This also has a cable mechanism for manual adjustment.
Blue pipe from 7 way tube goes to actuator for distribution flap.
Black pipe from 7 way tube goes to actuator for air inlet vent under bonnet.