Chevrolet Light Duty Truck 1973, Service Manual

Page: 550 / 979

6 Y - 2 2 E N G IN E E L E C T R IC A L
Fig. 6C—Basic Wiring Diagram
Switch Lamp Engine
OFF OFF STOPPED
ON
ON STOPPED
ON OFF RUNNING
these two terminals, or by an open in the circuit.
This condition can cause an undercharged Ener­
gizer. To determine where an open exists, proceed
as follows:
a. Connect voltmeter from No. 2 generator
terminal to ground. If reading is obtained, go to
step b. If reading is zero, repair open circuit
between No. 2 terminal and Energizer. If lamp
now comes on, no further checks need be made.
b. With ignition switch on and with No. 1 and No.
2
terminal leads disconnected, at generator,
momentarily ground No. 1 terminal lead.
CAUTION: Do
not ground No. 2 lead.
c. If lamp does not light, check for a blown fuse, or
fusible link, a burned out bulb, defective bulb
socket, or an open in No. 1 lead circuit between
generator and ignition switch.
d. If lamp lights, remove ground at No. 1 terminal
and with No. 1 and No. 2 terminal leads
connected at generator, insert screwdriver into
test hold (fig. 7C) to ground winding.
e. If lamp does not light, check connection between
wiring harness and No. 1 terminal of generator,
and check brushes, slip rings, and field winding
as covered in Overhual Manual.
f. If lamp lights and voltmeter reading is obtained
in step a, replace regulator as covered in the
Overhaul Manual.
3. Switch On, Lamp On, Engine Running—The
possible causes of this condition are covered in the
"UNDERCHARGED ENERGIZER" section.
UNDERCHARGED ENERGIZER
CONDITION CHECK
This condition, as evidenced by slow cranking and low
specific gravity readings, can be caused by one or more
of the following conditions even though the ammeter
may be operating normally.
1. Insure that the undercharged condition has not
been caused by accessories having been left on for
extended periods.
2. Check the drive belt for proper tension.
Fig. 7C—Delcotron End View
INSERT SCREWDRIVER
GROUND TAB TO
END FRAME
END
FRAME
HOLE
LIGHT DUTY TRUCK SERVICE MANUAL