Chevrolet 10 Series 1970 Service Manual page 413

F ig . 3 d —Basic W irin g D iagram
1. Insure that the undercharged condition has not been
caused by a c c e s s o rie s having been le ft on fo r ex­
tended periods*
2. Check the d riv e b elt fo r p ro p er tension.
3. Check e n e rg iz e r. T e s t is not va lid unless e n e rg iz e r
is good and fu lly charged.
4. Inspect the w irin g fo r defects. Check all connections
fo r tightness and clean lin ess,
/connectors at the gen erator and fir e w a ll, and the
cable clam ps and b attery posts.
5o W ith ignition switch on connect a vo ltm e ter from
gen erator " B A T " term in al
NOo 1 term in al to ground, and gen erator No. 2 te r m i­
nal to ground. A z e r o reading indicates an opening
between vo ltm ete r connection and battery.
INSERT SCREWDRIVER
GROUND TAB TO
END
FRAME
HOLE
F ig . 4 d —D e lc o tro n End V ie w
including the slip
to ground, gen erator
END FRAME
NOTE: If previou s Steps 1 through 5 check
s a tis fa c to rily , check
follow s:
6. Connect a vo ltm eter in the c ircu it at the " B A T "
term in al o f the gen erator,
7. O perate engine at m oderate
1500-2000 rpm ) and turn on e le c tric a l loads (high
beam headlights, w indshield w ip er, heater o r A/C
b lo w er, radio, etc.).
NOTE: Without sufficient e le c tr ic a l load to de­
mand maximum D elcotron output the follow in g
voltage check is invalid.
8. O b serve V oltm eter reading:
a. If reading is 12.8 volts o r m ore, gen erator is
not d efective. Turn
engine and disconnect test equipment. Recheck
Steps 1 thru 5.
b. If reading is le s s than 12.8 volts, ground field
winding by in sertin g a s c re w d riv e r into the test
hole in the end fram e (fig . 4D).
CA UTIO N: T A B IS
C ASTIN G SU R FAC E DO NO T FORCE SCREW ­
D RIV ER D E E PE R TH AN ONE INCH IN TO END
F R A M E .
(1) If voltage in crea ses (13 volts and above)
regu lator unit is d efective. Replace regu la ­
tor, as d escrib ed in Section 6Y, Chassis
Overhaul Manual. Repeat Steps 7 and 8 after
new regu lator unit is installed.
OHMMETER
INSULATING
WASHERS
CAPACITOR
ATTACHING
RECTIFIER
BRIDGE
F ig . 5 d —S lip Ring End Frame
ENGINE-ELECTRICAL 6Y-21
D elcotron gen era tor as
speed (approxim ately
o ff e le c tric a l loads, stop
W IT H IN 3/4 INCH OF
OHMMETER
DIODE
TRI°
n uts
CHEVROLET TRUCK SERVICE MANUAL