Chevrolet 70 1969 Series, Shop Manual

Page: 377 / 913

ENGINE ELECTRICAL 6Y-6
C A R E O F N E W B A T T E R I E S IN S T O R A G E
N e w batteries
in storage should be stored and
cared for in accordance with instructions furnished
by the battery manufacturer.
P R E P A R I N G D R Y - C H A R G E D
B A T T E R I E S F O R S E R V I C E
Electrolyte should be added to dry-charged
batteries in accordance with instructions furnished
by the battery manufacturer.
BATTERY CABLES
Excessive resistance caused by terminal con­
nections and partial short circuits through defec­
tive cable insulation will result in abnormal volt­
age drop in starter cable. Low voltage at starter
will prevent normal starter operation and will
cause hard starting. The following tests must be
made with primary wire disconnected from dis­
tributor or coil or with Diesel stop knob pulled
out to prevent engine starting:
1. Check voltage drop between grounded (-)
battery terminal and vehicle frame. Place one prod
of test voltmeter on grounded battery post (not on
cable clamp) and the other on frame. Operate
starter and note the voltage reading.
2. Check voltage drop between ungrounded (+)
battery terminal and starter terminal stud with
starter operating.
3. Check voltage drop between starter housing
and frame with starter operating.
4. If voltage drop in any of the above tests is
more than 0.5 volt on gasoline models or 1.0 volt
on Diesel models, there is excessive resistance
in the circuit. To eliminate resistance, the cables
should be disconnected and connections cleaned. If
cables are frayed or the clamps excessively cor­
roded the cables should be replaced. When select­
ing new cables, be sure they are at least as large
as the old ones.
SPECIFICATIONS
B A T T E R Y MODEL A PPLICA TIO N
ST A NDA RD PART NO.
H M /JM /T M .-8 0 .................................................................................................................................................................... 1980038
H V /JV / T V -7 0 ..................................................................................................................................................................... 1980760
OPTIONAL
H M /JM /T M -8 0 (2 -B a tte rie s in S e rie s)....................................................................................................................... 1980926
H M /JM -8 0 ................................. ............................................................................................................................................. 1980974
B A T T E R Y SP EC IFIC A TIO N S
PART NO. M O D E L NO. CATALOG
NO.
VOLTS
NO. OF
PLATES
PER CELL
AMP. HR.
CAPACITY AT
20 HR. RATE
CRANKING
ABILITY AT
0° F.
1980038 9MJ6A Y-71
12 11 70
2.0 Min. at 300 Amp.
1980760
8DR-205 760
12 27 205 10.5 Min. at 300 Am p.
1980926
3H-926
926 6 21 145 6.0 Min. at 300 Amp.
1980974
9H9-974 974 12
15 85 2.8 Min. at 300 Amp.
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK S H O P M A N U A L