Magneto switch issues
 

Seems i know far less than i thought about magneto ignitions.
I have a US41 on a Phaeton 90. Has a little toggle switch on the cowl. Switch it on and the engine will start. Flip it off and the engine quits. Bought the model used and flew it several times with no problems.
So i get the bright idea to install a Tx controlled kill switch. In the process of installing a servo operated limit switch, i removed the wire from the coil. After installing the new switch, neither switch would kill the engine. I thought id put the coil wire back on the right connector, there are 3 possibilities. I have removed the remotely operated switch and thoroughly checked the other manual switch with a meter, clearly marking open and closed positions. I cant seem to find which terminal on the coil that the grounding wire needs to be on. Can anyone enlighten me.
Thanks
sp

SP,

Forgive me if I get into fundamentals you know in your sleep, but I will start from the beginning. Your kill switch on a magneto-ignited engine is a grounding switch. When the switch is "on", the ignition is grounded. No engine operation. If you want a manual switch and a servo operated limit switch, they need to be wired in parallel so that either can independently ground the magneto. Wire them both up, but do not plug into the magneto. Test start the engine (assuming you can kill the engine through the throttle). The engine should start. If it doesn't you have other issues. Plug in in one of the switches and leave it in the 'open' or off position. Engine should still start and should be killed by closing the switch ('on' position). Plug in the second and repeat.

I have a Quadra 42 and US41 I have operated for years and I only remember one blade into which I could plug the kill switch. You should be able to test start and kill the engine to identify what is going to work for you.

Good luck,

Bedford

Bedford
Thanks so much for taking the time to write it all out. Its finally sinking in. I had the grounding wire on the wrong spade terminal. Better lighting and reorienting the shoe and wear patterns matched. Got it on the correct one now. Meter confirms open and closed. I have the open or run position labeled Spark and the closed or off position is labeled Ground. Keeps me from having to think bassakwards about on/off and open/closed.
Thanks again.
sp