> Okay, electrical boffins - it's my turn to ask for help!
> Spent two days rebuilding and refitting the metering unit on my
> PI and came
> the time to start it all up. Switched on ignition but as soon as
> the starter
> began cranking the rev counter needle shot round the dial and
> lodged itself
> firmly on the underside of the needle stop. I incline to the view "that
> something is amiss" but having never been too skilled (and even
> less aware)
> of the whys and wherefores of solid state electrics. Incidentally, rev
> counter is made by Jaeger. Thanks in antickypation
John, there were two different types of rev counter in common use and I'm
not sure which one your car would have (not even certain which car we're
discussing here) ...
For one type (as found on my early Stag) I don't see how this would be
possible (except for a fault in the tach itself).
For the other (later on the Stag) type, a poor power connection (possibly
even a blown fuse) or a bad ground to the tach housing might cause this
symptom. I don't think it would be sensitive to mis-wiring at the coil, but
I don't have a schematic for it handy, so it's possible I'm wrong about
that.
The later type should have a white/slate wire from the point side of the
coil, for the earlier type the white/slate gets connected to the power side
of the coil (or ballast resistor if one is present).
Randall
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