When I recently had my ZB engine rebuilt, they "lost" the original water
temperature sending unit. On the Z Magnette it is an electrical sending
unit, so the MG "specialist" substituted a unit for a late model MGB.
Unfortunately the unit does not work with the Z Magnette's water
temperature gauge, staying on "cold" regardless of the driving conditions.
Does anyone have an extra Z Magnette water temperature sending unit???
I've tried various MG and MG Z Magnette parts sources, and even MORGAN (I
was told they used the same gauge/sending unit in the mid-50s-60s) without
luck at locating a replacement. No, I am not yet to the point of cutting
up my wood fascia to install an MGA mechanical sending unit and gauge.
Since the ZB and MGB sending units seem to be of bi-metal construction, I
am assuming that the intended design is to measure electrical resistance as
temperature varies. Since I cannot get the gauge off of "cold" I am
assuming the newer sending unit has far more resistance built in than the
original gauge has capacity for. I know how to add resistance into a
circuit, but how can I reduce it? Does anyone have experience with
recalibrating electrical-based water temperature gauges? SMITHS/JAEGER
rebuilders sound like I would have to pay for them to learn/figure it out
as much as me; and I work cheaper :-).
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