Common feed for ECU and COIL
 

Per Bob Nuckles today on aero electric digest, a common feed can cause dirty power and confusion in the CPU.

I replied on that list. I think this is more complex than "shared bus bad discrete bus good." I suspect it has a lot to do with length and gauge of wire. What I don't have a good handle on is how much fuses/breakers/switches change this.

Terminating the ECU and coil at the end of 10" of 10gauge wire is no big deal, doing the same over 18gauge wire matters more, but probably still no big deal, but through 18gauge wire to a shared switch and breaker? I have no idea.

I do know that the backup battery shares the coil and ECU over 18G wire and a single fuse.

schu