The small gauges don't have grounds as such anyway, only through their
respective senders, and the ground for the fuel gauge is completely
different to the other two. Ditto the ground for the brake lights is
completely different from the others.
If you are saying the tach fails as well then you are right to discount the
stabiliser, ditto the oil gauge apart from 1967, as these gauges don't use
the stabilised voltage.
If the stabiliser ground fails then the symptom is that the stabilised
gauges read *high*.
If *all* the green circuits have failed, and this includes washers, wipers,
heater fan (on all but 73 and 74 models) and reverse lights then the problem
is almost certainly the fuse or its holder. If some of the green circuits
are OK then it could still be the fusebox as most years have two spade
connectors so one of these could be faulty. If not that then one of the
many 4-way bullet connectors dotted around the wiring. FWIW 73 and 74 cars
have the washers, wipers and heater fan powered from their own in-line fuse
from the accessories position of the ignition switch.
Pertronix causing high tach readings on 72 and earlier cars is quite common.
These use a current pulse for the tach instead of a voltage pulse used on
later cars. The pick-up uses the white from the ignition switch making one
full turn (two passes) through the pickup, on its way to the coil +ve. You
could try altering the pickup wiring so it only makes one pass through the
pickup, but this will probably entail opening up the tach as the pickup is
internal on later cars, it was external and hence easier to get at on
earlier cars.
PaulH.
----- Original Message -----
> 71 BGT gauges work intermittently...
>
> Also, brake lights do not work.
>
> Additionally, the tach reads high (when working).
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