Static Checks; System Condition Test; Adjust Voltage Setting; Voltage Setting Test Connection - Chevrolet 10 1971 Series Chassis Service Manual

DO NOT TURN THIS NUT
UNDER AN Y C O ND ITIO N
Fig. 3c-Adjust Voltage Setting

STATIC CHECKS

Before making any electrical checks, perform the fol­
lowing static checks:
1. Check for loose fan belt.
2. Check for defective battery. (Refer to Battery.)
Inspect all connections, including the slip-on connec­
3.
tors at the regulator and Delcotron.
Do not short field to ground to check if
NOTE:
generator is charging since this will seriously
damage the charging system.
SYSTEM CO NDITION TEST
This test is used to indicate the overall condition of the
charging system (both good and defective) and to isolate
the malfunctioning unit if the system is defective.
ADJUSTING SCREW
(Turn To Adjust
Voltage Setting)
Fig. 4 c -V o lta ge Setting Test Connection
1. With ignition off, perform the prescribed Static Checks
outlined in this section. Then set hand brake and shift
transmission into neutral.
2. Connect a voltmeter from junction block on horn re­
lay to ground at regulator base.
Be sure meter clip does not touch a
CAUTION:
resistor or terminal extension under regulator.
3. Connect a tachometer on engine.
4. Models equipped with Indicator Lamp: Turn ignition
''
switch to "ON position and check indicator lamp. If
lamp fails to glow, perform appropriate tests and
corrections (Indicator Lamp Circuit Tests) before
continuing.
Models equipped with Ammeter:
"ACC"
switch to with an accessory on and check
ammeter. If ammeter fails to read discharge, check
ammeter circuit before continuing.
5. Models equipped with Indicator Lamp: If lamp glows,
start the engine and run it at 1500 rpm or above.
Check indicator lamp. If lamp fails to go out, per­
form appropriate test and corrections (Indicator Lamp
Circuit Test) before continuing.
Models equipped with Ammeter: If ammeter reads
discharge, start the engine and observe ammeter. If
ammeter fails to move toward charge (from original
position), perform appropriate test and corrections
(Field Circuit Tests) before continuing.
At this point a field circuit has been
NOTE:
established and any other problem will lie in
generator or regulator.
6. Turn on high-beam headlights and heater blower
motor to high speed, run engine at or above 1500
rpm (for a few minutes, if necessary) and read the
voltage on meter.
Voltage will not greatly exceed 12-1/2
NOTE:
volts until the battery developes a surface charge,
a few minutes generally, unless the battery is
severely discharged or is hot.
If reading is:
ENGINE-ELECTRICAL 6Y-9
Turn ignition
10-30 CHEVROLET TRUCK SERVICE MANUAL