"Anyway, is anyone having any luck with an altitude switch/light which acts as a reminder to turn the low boost pump on when climbing above 10,000 feet and turn it off when descending below 10,000 feet?"

Sunday Evening
1/28/07

Dan,

We are in the process of wiring our IV-P and the avionics shop, that I have had helping me do the wiring, designed a circuit using a Pressure Controls AV-1 altitude pressure switch as a signaling device.  The circuit turns on an annunciator light ("Boost Pump") whenever the aircraft climbs through 10K feet and when the boost pump is turned on, the light goes out.  When descending through 10K feet, the "boost pump" light will come back on and whenever the pump is turned off, the light goes out.  The circuit tests "as designed" on the bench, but has not been put into actual service yet - the only missing ingredient is the test on the pressure switch.

If you are interested in the details, just let me know.

Ed Smith
Chesapeake, VA