Chevrolet 70 1969 Series, Shop Manual

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ENGINE ELECTRICAL 6Y 24
W IRING HARNESS
CONNECTOR AT REGULATOR T-641-1
Figure 6 — Generator Output Test— Jumper Lead
Connection at Regulator (Typical)
5. Connect a tachometer to engine, then con­
nect positive cable to battery and start engine.
Adjust engine speed and carbon pile (if used) or
with vehicle accessories to provide rated voltage.
Ratings for each generator are given in "Specifi­
cations" at end of this section. If generator does
not produce current within its rated capacity, it
can be considered defective and in need of repair.
N O T E : Procedure for replacing generator are
given later.
6. Remove instruments and jumper lead and
connect wiring harness connector to regulator.
7. If no defects were discovered by the fore­
going tests, yet the battery remains undercharged,
adjust voltage regulator setting as explained under
applicable regulator later in this section.
REGULATOR VOLTAGE TEST
(ON VEHICLE)
The voltage at which the regulator operates,
varies with changes in regulator ambient temper­
ature which is the temperature of air at a distance
of 1/4-inch from the regulator.
G E N E R A T IN G S Y S T E M W IT H
TW O- UN IT T Y P E R E G U L A T O R
1. Refer to Figure 7 which shows all test
equipment connected into system. Figure 8 shows
use of special adapter and jumper lead at regulator.
2. Connect an ammeter and a 1/4-ohm resis­
tor with a rating of 25 watts or more in series in
Figure 7— Connections for Testing Regulator Voltage
Setting (Two-Unit Type Regulator)
the circuit at the " B A T " terminal on the generator
(fig 7). In the event the battery is discharged, the
1/4 ohm resistor will limit the generator output to
10 amperes or less which is required, when check­
ing and adjusting the voltage setting.
3. Install special adapter as shown in Figure
7. Use a 25 ohm 25 watt variable resistor in
series with the generator field windings at the
regulator " F " terminal, and connect a jumper lead
from the #3 adapter lead to the generator " B A T ”
terminal as shown. Connect a voltmeter from the
#3 adapter lead to ground as shown. Turn the re­
sistor to the closed or "no resistance" position.
Figure 8— Testing Voltage Setting
(Two-Unit Type Regulator)
CHEVROLET SERIES 70 -80 H EAVY DUTY TRUCK S H O P M A N U A L