Darren Pond wrote: > Is it acceptable to use the Keyed off/run/start switch as master > switch (battery solenoid)?
That's the way mine is, but I'm using a high quality Cole-Hersee (http://www.colehersee.com/catalog_top/index.htm ) switch that's rated for 10 amps @12V (don't know the part number, since it's been ten years). I wouldn't do that with some unknown-quantity auto parts store switch that had no ratings on the package though. Contactors fail too, so to me, that's just another failure mode that I'd be building in if I had one. Having said that, the "backup" is my DPDT (double pole, double throw) switch that swaps out both ignition systems and fuel pumps. The "secondary" circuit is powered by the backup battery, with the output powering the backup fuel pump and the secondary ignition coil ONLY. I'm even sufficiently paranoid to have tried to run them such that if something fried in the primary system, no melted wires would affect the "secondary" system. There are some more details on this are at http://home.hiwaay.net/~langford/fuel/index.html . What I like most about this system is that it's just like starting a car in practice, and if there's any kind of hiccup, if I switch that one switch from left to right, and things don't improve, I already know that (other than carb heat), there's not much I'm going to be able to do about the failure other than continue to "fly the plane" and start concentrating on picking out a landing spot... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --------------------------------------------------------------
