Chevrolet 70 1969 Series, Shop Manual

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ENGINE ELECTRICAL 6Y-31
REGULATOR ADJUSTMENT
N O T E : Refer to "Charging System Trouble
Analysis Chart" later in this section for proced­
ures for analyzing and checking charging system
malfunctions.
1. Connect (POS) voltmeter lead to battery
(POS) terminal on regulator and (NEG) voltmeter
lead to ground on regulator.
2. Adjust engine speed to approximately 1500
rpm, then turn heater to medium speed and turn
all other electrical load " O F F . ” Disconnect (NEG)
cable from battery.
3. Place a thermometer (J-8529) approximate­
ly %-inch from regulator cover and operate for
approximately 15 minutes.
4. Compare voltmeter reading with those given
under applicable regulator in "Specifications" at
end of this section.
5. If voltmeter is not within limits listed in
"Specifications.” remove plug from regulator cover
and insert a thin-bladed screwdriver into adjust­
ment screw.
N O T E : After two notches in either direction
there is a positive stop.
IM P O R T A N T : Do not force adjusting screw
beyond normal stop. Forcing the screw beyond the
normal stop will destroy the regulator.
6. For an undercharged battery, raise voltage
setting by turning adjusting screw one notch (clock­
wise) then check for an improved battery condition
after a service periof of reasonable length.
7. For an overcharged battery, lower voltage
by turning adjusting screw one notch (counterclock­
wise), then check for an improved battery condition
after a service period of reasonable length.
8. If the regulator cannot be adjusted to with­
in limits listed in "Specifications" at end of this
section, repair or replace the regulator.
REGULATOR REPLACEMENT
A N D REPAIR
R E G U L A T O R R E M O V A L
1. Disconnect the negative battery cable from
battery,
2. Carefully lift up on regulator wiring har­
ness connector with one hand and with the other,
pull harness connector from regulator.
3. Remove regulator mounting screws, then
remove regulator assembly.
R E G U L A T O R R E P A IR
With the regulator on work bench remove the
cover and inspect various components, connections,
and field relay contact points for signs of damage.
if field relay contact points are dirty or oxi­
dized, they should be cleaned. The contact surfaces
may oxidize and develop a slight cavity. These
surfaces should be cleaned to bare metal using a
riffler file.
IM P O R T A N T : D O N O T file excessively.
If the voltage regulator cannot be adjusted to
within specifications listed at end of this section,
replace the regulator assembly.
R E G U L A T O R IN S T A L L A T IO N
IM P O R T A N T : Make sure one battery cable is
disconnected from battery.
1. Place regulator-to-generator ground wire
on regulator mounting and install regulator attach­
ing screws.
2. Lift up on regulator terminal latch and in­
sert wiring harness connector over regulator term­
inals.
IM P O R T A N T : Make sure connector is fully
engaged over terminals and locked in position.
Check by attempting to pull connector apart.
3. Connect battery cable to battery terminal.
CHEVROLET SERIES 70 -8 0 H EAVY DUTY TRUCK SH O P M A N U A L