Chevrolet CHEVY VAN G10 SERIES Service Manual page 222

A t regular intervals, inspect the term inals for corrosion and
loose connections, an d the wiring for frayed insulation. Check
m ounting bolts for tightness. C heck th e drive belt for
alignm ent, proper tension and wear. Because o f th e higher
inertia and load capacity o f th e roto r used in A.C. generators,
PR O PE R BELT TENSION is more critical th an on D.C.
generators.
Since the D elcotron and its com panion regulator are
designed for use on negative polarity system s only, the
follow ing precautions m ust be observed. Failure to observe
these precautions may result in serious damage to the charging
system .
1. When installing a b attery , always m ake absolutely sure
th e ground polarity o f th e b attery , generator and regula­
to r is the same.
2. When connecting a booster b attery , m ake certain to
connect th e correct b attery term inals together.
3. When connecting a charger to th e b attery , connect the
correct charger leads to th e b attery term inals.
4. Never operate th e generator on an uncontrolled open
circuit. Make absolutely certain all connections in the
circuit are secure.
5. Do not short across or ground any o f the term inals on
th e generator or regulator.
6
. Do n ot attem p t to polarize the generator.
7. Do not disconnect lead at generator w ith o u t first dis­
connecting b attery ground cable.
Trouble in th e A.C. charging system will usually be indi­
cated by one or m ore o f the follow ing conditions:
1. F aulty indicator lam p or am m eter operation.
2. A n undercharged b attery (usually evidenced by slow
cranking speeds).
3. An overcharged b attery (usually evidenced by excessive
b attery w ater usage).
4. Excessive generator noise or vibration.
The follow ing series o f on-the-vehicle quick checks w hich
are designed to assist th e service technician in locating troubles
w ithin th e various com ponents o f th e engine electrical system.
A dditional checks, adjustm ents and overhaul procedures o f
these com ponents are also described in " The Overhaul
M anual" and should be referred to as necessary.
STATIC CHECKS
Before making any electrical checks, perform the following
static checks:
1. Check for loose fan belt.
2. Check for defective b attery . (R efer to B attery.)
3. Inspect all connections, including the slip-on connectors
at th e regulator and D elcotron.
N O T E : Do not short field to ground to check if
generator is charging since this w ill seriously damage
the charging system.
MAINTENANCE AND ADJUSTMENTS
SYSTEM C O N D ITIO N TEST
This test is used to indicate th e overall co n d itio n o f the
charging system (b o th good and defective) and to isolate the
m alfunctioning u n it if th e system is defective.
1. With ignition o ff, perform the prescribed S tatic Checks
outlined in this section. Then set hand brake and shift
transm ission in to neutral.
2. C onnect a voltm eter from ju n ctio n block on horn relay
to ground at regulator base.
C A U T IO N : Be sure meter clip does not touch a
resistor or term inal extension under regulator.
3. C onnect a tachom eter on engine.
4. Models equipped w ith Indicator Lam p: T urn ignition
sw itch on " ON " position and check indicator lamp. If
lam p fails to glow, perform appropriate tests and correc­
tions (Indicator Lam p Circuit Tests) before continuing.
M odels equipped
sw itch to " ACC" w ith an accessory on and check
am m eter. If am m eter fails to read discharge, check
am m eter circuit before continuing.
5. Models equipped w ith In d icato r Lamp: If lam p glows,
start the engine an d ru n it at 1500 rpm or above. Check
indicator lamp. If lam p fails to go o u t, perform ap p ro ­
priate test and corrections (Indicator Lam p Circuit Test)
before continuing.
Models equipped w ith A m m eter: If am m eter reads
discharge, start th e engine and observe am m eter. If
am m eter fails to move tow ard charge (from original
position), perform ap propriate test and corrections (Field
Circuit Tests) before continuing.
N O T E : A t this point a field
established and any other problem w ill lie in gener­
ator or regulator.
Fig. 3c—Adjust Voltage Setting
ENG INE E LEC TR IC A L 6Y-11
w ith A m m eter: T urn ignition
circuit has been
C H E V Y V A N SHOP M A N U A L