Pontiac FIREBIRD 1972 Service Manual page 809

ENGINE ELECTRICAL 6E-47
The "A" terminal is activated only when the ignition
switch is in the "ACCESSORY" position, and the "S"
and "G" terminals are activated only in the "START
position. All circuits are cut off in either the "OFF" or
"OFF-LOCKED" positions.
When the ignition switch is turned to the "START" posi-
tion, the ignition primary circuit isactivated by the starter
solenoid, which by-passes the re'sistance wire to the coil,
and the starting motor circuit is activated to crank the
engine.
Two IGNITION terminals, marked "11" and "I3", will
be found on the back of the switch. The "11" and "13"
terminals are energized when the ignition switch is in the
normal operating position ("RUN" position). The "11"
directs current to the ignition coil through the resistance
wire. "13" energizes the air conditioning, heater and de-
froster circuits.
When the ignition switch is in the "RUN" position, cur-
rent can be traced from the battery through the battery
terminals (Bl, B2 and B3), through the voltage regulator
to the field terminal of the generator, and finally through
the rotor field coil windings to ground.
REPLACE SWITCH, LOCK CYLINDER OR FREE UP
LOCK CYLINDER
Refer to GENERAL INFORMATION (Section O ) , and
for ignition switch and lock cylinder repair procedures.