John,

   I do electronic troubleshooting for a living. Usually,
when I have repeated failures of a single module it's
because something else to which it is connected is "eating"
it. A likely candidate is a sensor that has too low
impedence/resistence and therefore is passing too much
current. Less common in recent years is voltage on the
return line.  It's amazing how dead a component will get
with as little as -1.5V on a line that's supposed to be
zero.

You also might consider getting a voltage regulator
for the B+ going into the EC2.  I don't have ready access
to specifics right now, but regulats\or ASICs are a fairly
standard item.  It might be worth putting a scope on
your charging circuit to see what kind of spikes the
alternator regulator is actually allowing out on the
+12V line.  The RMS voltage (okay, I know that DC isn't
actually measured in RMS) could be 14.2V but the regulator
could still be allowing mSec length 20V spikes to pass
through.  ['course you have to get it *running* again to
check for that  :)  ]  A separate regulator for the EC2
might buy you the time you need to find a B+ problem.

   I'd come out and help you look for it, but it's a 2000
mile flight, and I still have to work next week.

Regards,
Dale R.


> From: "John Slade" <sladerj@bellsouth.net>
> Date: 2005/05/20 Fri PM 08:51:53 EDT
> ...
> The test went well. We plugged my EC2 into Buly's harness and immediately
> got the NOP message on his EM2. We didn't check the spark, but the engine
> would not fire at all. We then reinstalled his EC2. The NOP message went
> away, and the engine fired up immediately on cranking. There we have it. My
> EC2 is dead. Next question - why is it dead, and did I fry it when I
> connected it to the old wiring? Have I corrected the problem by rewiring
> everything? Of course, we could have tested my wiring by installing Buly's
> EC2 in my plane. He didn't offer, and I didn't ask :)
> ...