As I read your quote from the placards, "Turn fuel transfer pump off when light is on" means that once the mains are empty of fuel and fuel pressure to the switch drops...the light THEN comes on (to warn you to turn the pump off).
Assuming this to be true, so long as "...the pump is transferring fuel to the header tank, the light should be..." OFF, because that is "normal" operation so long as there is fuel in the mains! It is counterintuitive to have a red light on during "normal" operation. A red light is a warning or alert condition notification. If it is connected so that the reverse is true, it would appear that this should be changed. Regards, WRB -- On Jul 30, 2009, at 12:48, hogowner82 wrote: > I still trying to understand how the electric fuel pump transfer > system is supposed to work on the O-200 conversion. The placards say, > "Turn on to keep nose tank full", and "Fuel transfer pump warning. > Turn fuel transfer pump off when light is on". I understand that the > fuel pump is supposed to run continually while in flight to keep the > header tank full. The warning light is wired from alternator positive, > through a 4psi normally open pressure switch to ground. So as long as > the pump is transferring fuel to the header tank, the light should be > on. When the wing tanks are empty, the flow will stop, the pressure > drops and the light goes off. Is the placard wrong, or am I missing > something?
