In a message dated 97-10-31 07:19:40 EST, egil@kvaleberg.no writes:
> On 31 Oct 1997, Joe Curry wrote:
>
> > One lead goes to the coil negative connection
> > One goes to Ground
> > The third goes to Power and the voltage stabilizer.
To which Egil replied:
> The trad. 70s Lucas electronic Tacho is connected in *series* with the
> coil. So it requires that the connection between the coil and the points
> is routed *via* the tach. So you need two wires for this. The standard
> connectors at the tach are such that it is easy to connect them should you
> ever need to remove the tach for servicing etc. Failing to do that will
> cut the ignition if you remove the tach.
>
> In addition to these two wires, you need a supply and ground wire, as you
> noted. Plus a wire to the instrument lighting, of course.
>
> > You always have theoption of an after-market one.
>
> They will usually connect as you have noted, with ONE wire to the coil.
Egil:
Lucas also supplied the type tachometer as described by Joe. The type you
mentioned was used in MGBs, while the other type was used in Spitfires (at
least in the later years).
There is one error in what Joe said about connecting a tachometer that needs
to be corrected. The tach should NOT be connected to the voltage stabilizer
that supplies the other gauges. First of all, it is not required, as the tach
has its own internal regulation. Secondly, the existing regulator is designed
to provide the correct output voltage with a specific load, based on the
gauges which were installed by the factory. Adding another gauge will change
the output voltage, making the gauges read even less accurately than they
already do. The voltage will be lower, making the gauges read less than they
should.
Dan Masters,
Alcoa, TN
'71 TR6---------3000mile/year driver, fully restored
'71 TR6---------undergoing full restoration and Ford 5.0 V8 insertion - see:
http://www.sky.net/~boballen/mg/Masters/
'74 MGBGT---3000mile/year driver, original condition
'68 MGBGT---organ donor for the '74
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