> Are those readings what we should expect for electronic ignition?
It depends a bit on the ignition, but those values are reasonable. If you think
of the ignition as simply being an electronic replacement for points and
condensor, what you are seeing is the condition when the points are open.
> It
> seems like there should be 12 volts from the positive side of the
> coil to the negative side of the coil with the key on but we're
> getting a reading of 0.
Again comparing to points, you would see 12v only with the points closed.
> Is there a problem in the electronic
> ignition controller?
Unfortunately, what you saw is also consistent with a failed electronic
ignition. Or it could be that whatever it uses for a pickup has failed (or is
disconnected).
My suggestion would be to connect a 12v test lamp across the coil, and watch it
while you crank the engine with the key on. You should be able to see the lamp
flash or glow with the engine turning. If it does not, then the electronic
ignition is not working for whatever reason.
> Should we scrap the electronic ignition and go back to
> the original ignition with new points and condenser? Where should we
> go from here?
If the above test fails, then my suggestion for "next step" would be to convert
back to points and condensor, at least temporarily. I carry a spare point plate
in my TR3A, complete with points and condensor, in case the electronic module
fails on the road somewhere. (Used it on the way to VTR 2000, too.) The point
plates are fairly universal, almost any Lucas 23D4, 24D4 or 25D4 will work,
which covers probably 95% of all 4 cylinder British cars from the 60s. TR3-4A,
MGA, MGB, at least some Mini, Sprite and so on. The one I carry is from a late
MG Midget I found in a local junk yard. Complete distributors go by frequently
on eBay, and particularly ugly ones sell for less than $10. The point plates
almost never wear out or break.
I don't know about other makers, but Crane will take back their ignitions and
repair them for less than the retail price of a new unit. Most likely the
result is better than new, IMO. YMMV of course.
Randall
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