Starter Motor; Relays; Oil Pressure Switch - Triumph Spitfire MK3 Handbook

ELECTRICAL SYSTEM

Starter Motor

The starter motor, mounted on the rear left-hand side of the
engine, is operated by a solenoid switch (Fig. 51) which is
remotely controlled by the ignition switch, or manually
controlled by pressing the end of the solenoid thus causing the
crankshaft to rotate as required whilst working over the engine
compartment. The solenoid is attached to the bulkhead adjacent
to the battery
34
IMPORTANT. Before manually operating the starter solenoid
make quite sure that the gear lever is in "Neutral" and the
handbrake is firmly applied.
Should the starter pinion jam in mesh with the flywheel, it
may be released by switching off the ignition, selecting top gear,
and rocking the car to and fro, or by turning the squared end of
the starter motor shaft in a clockwise direction, viewed from the
end of the shaft.

Relays

A relay (arrowed Fig. 51) is incorporated in the horn circuit,
and in the overdrive Circuit also, when an overdrive is fitted. The
relays are mounted adjacent to each other, on the centre of the
bulkhead in the engine compartment. Failure of a relay
necessitates renewal of the unit.

Oil Pressure Switch

An oil pressure switch contains a spring-loaded diaphragm
which opens a pair of contacts to extinguish a warning light on
the facia when the pressure exceeds 44 to 74 p.s.i. (0.22 to 0.53
2
kg/cm ). The switch is screwed into the side of the engine and
communicates, via a drilling, with the main oil gallery.