Pontiac FIREBIRD 1972 Service Manual page 779

ENGINE ELECTRICAL 6E- 17
Do not make this test before making preliminary checks unless battery
is being overcharged as evidenced by excessive water usage.
1.
lnsert 1/4 ohm resistor
(J
22087) at battery nega-
tive terminal.
-
2. Insert test probe into No. 3 terminal of voltage
regulator connector.
3. Connect voltmeter from test probe to ground.
4. Start engine and run a t 2000 r.p.m.
5.
Press on 1/4 ohm resistor to engage.
6. Observe voltage.
.
(
LESS THAN 13.5 VOLTS
I
lndicates low setting or defective regulator.
I
1. Shut off engine and remove regulator cover (dis-
connect connector while removing cover).
2.
Turn adjusting screw clockwise t o raise setting (see
Fig. 6E-26).
3. Replace cover and repeat test. I f regulator cannot
be set within range, replace.
NOTE: To ad just transistor voltage regulator:
1. Remove pipe plug
2. lnsert small screwdriver into slot.
3. Turn clockwise to raise setting
(0.3 volt for each notch moved).
13.5 TO 16.0 VOLTS
Charging circuit i s functioning properly.
Undercharged battery condition could be result of un-
noticed a c c e s s o r y operation or intermittent ground
causing battery drain.
NOTE: Voltage setting may be adjusted to owner's re-
quirements within this range.
MORE THAN 16.0 VOLTS
lndicates high setting or defective regulator.
1.
Shut off engine and remove regulator cover (dis-
connect connector while removing cover).
2.
Turn adjusting screw counterclockwise, pry spring-
holder up against screw head, and then turn screw
clockwise t o lower setting (Fig. 6E-26).
3. Replace cover and repeat test. I f regulator cannot
be set within range, replace.
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Fig. 6E-20B lODN Regulator Diagnosis