From:
guru1021_REMOVE_396433_THIS_@yahoo.com
The TCS or "transmission controlled spark" was an
emission device that shut off vacuum advance via a
firewall mounted solenoid in series with the vacuum hose
to the distributor. The 3rd/4th switch controlled
this solenoid. Also there was a thermal override
switch.(on my 74 Vega this was a dual connector switch that
also controlled the temperature "idiot"
light.)
Rare to find anyone still running this device or even
knowing what it was for. Great source of radio
interference too.
There may be 3 holes along the bottom of
the tailshaft housing. These were sometimes used to
hold a vibration dampner which consisted of a heavy
stack of steel plates riveted together with two
mounting arms.
Gary
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