My engine electrical system may look somewhat
complex. I'm using a dual ignition system as per the instructions of
Paul Messinger. See my engine pages for details.
In accordance with proposed electrical architectures in the
AeroElectric Connections, I use a contactor to totally disconnect the
alternator when turned off. Apparently, some failure modes may allow
the B-Lead to turn wild. I don't have a large breaker in the
cabin for the alternator. I'm using a current limiter (big fuse) in
front of the firewall. I also use a separate starter
contactor. Bob (AeroElectrics) has a good explanation for this on
his web site. On top of his justifications, I felt it allowed me to
completely build my electrical system (except for one connector to the
starter) even though my reduction drive and starter are not in place.
The EIS system generates quite a few wires in this area since all
senders are electrical.
You may notice a small relay in the center section of the firewall.
This is my automatic tach selector. I'll see if it works
later. When ignition 2 is off, it takes the tach signal from the
ignition 1. And it takes it from ign 2 if ign 2 is turned on.