Chevrolet 10 Series 1970 Service Manual page 407

POSITIVE
END
FRAME DIODES
NE
CASE
DIODES
W IR IN G H A R N E S S
14c—
F ig . V o lta g e Tests
CASE BRUSH
ASSEMBLY
SLIP
RINGS
GREASE
RESERVOIR
BALL
BEARING
HEAT
SINK
F ig . 13c — 130 A M P Series 4 D , Type 150 D e lco tro n
VO LTM ETER
ROTOR ASSEMBLY
STATOR
SLIP RING
ASSEMBLY
END FRAME
a. V oltm eter reads z e ro - rela y O.K.
b. V o ltm eter reading battery voltage - re la y points
stuck closed o r rela y damaged.
Turn the switch on and read the vo ltm eter.
3 .
a. V oltm eter reads battery voltage - re la y O .K.
b. V oltm eter reads
open circu it in w irin g to rela y
4. Make n ecessary re p a irs and recheck.
To Test The G enerator Field Circuit
1. Connect the vo ltm e te r to test adapter as shown in
Figu re 14c P a rt 2.
2. Turn the switch on and read the vo ltm eter.
a. If vo ltm eter reads
voltage, fie ld is O.K. - check gen erator output.
b. If voltm eter reads ze ro , an open circu it in the
regu lator it s e lf is indicated.
c. If vo ltm eter reads battery voltage, look fo r an
open fie ld winding o r a shorted regu lator.
Test The Field as Follows:
IMPORTANT: The regu lator defect may have
been caused by a d efective
Check the field as follow s b efore installin g the
new regu lator.
1. Turn the switch o ff and disconnect the battery ground
strap.
2. Disconnect the adapter fro m the regu lator.
Connect an ohm m eter to the adapter as shown in
3 .
Figu re 15c.
4. If the ohm m eter reads high, there is an open, o r
ex cessive resistan ce in the fie ld winding, o r in lead.
ENGINE-ELECTRICAL 6Y-15
GREASE BALL
RESERVOIR BEARING
z e ro - rela y winding bad
1-2 volts le s s than battery
gen erator field .
CHEVROLET TRUCK SERVICE MANUAL
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