Chevrolet DB90 Series, Руководство по обслуживанию

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S ec. 6Y -136
A. C. GENERATING SYSTEM (NON-INTEGRAL TYPE)
3. Turn on ignition or control sw itch, but do
not sta rt engine.
4. If the two voltm eter readings total m ore
than 0.3 volt, check for e x c e s s iv e r e sista n c e in
lead s betw een battery and field relay, between field
rela y and regulator, and between regulator and
generator. If th ese lead s a re sa tisfa cto ry , replace
the relay.
5. R em ove jumper lead connected between
battery and No. 2 term inal on fie ld relay and con­
nect lead to No. 1 and No. 3 term inal on r ela y .
VOLTAGE SETTING ADJUSTMENT
NOTE: A voltage settin g not tailored to m eet
v eh icle requirem ents can resu lt in an undercharg­
ed or overcharged b attery. Adjust voltage setting
a s follow s:
1. Connect a voltm eter to the adapter a s shown
in View A, figure 17.
2. Connect an am m eter in circu it at output
"BAT" term inal on the generator.
3. Turn a ll a c c e s s o r ie s off.
4. Operate generator at approxim ately 3,000
rpm and check for rated output.
NOTE: Output should be at le a st 10 am p eres
below rated generator output for th is check.
5. To adjust the voltage settin g, rem ove plug
from regulator cover and turn slotted adapter
in sid e the regulator as follow s:
NOTE: A fter two notches in each direction,
th ere is a p o sitiv e stop.
a. For an undercharged battery, r a ise v o lt­
age settin g by turning adjuster one notch clock w ise
toward the "+" mark on cover.
b. For an overcharged battery, low er the
voltage settin g by turning the adjuster one notch
cou n terclock w ise toward the mark on cover.
c. If regulator cannot be adjusted to a value
within lim its liste d in "Specifications" at end of
th is sectio n , replace the regulator.
Figure
18—A d ju stin g V o lta g e Setting
ITw o-Unit Type Regulator) ITypical)
ADJUSTING REGULATOR VO LTAGE
SETTING (WITH 1119507 OR
1119515 REGULATOR)
The proper voltage settin g is attained when
the battery rem ain s fully charged with a minimum
u se of w ater.
The voltage at which the regulator op erates
v a r ie s with changes in regulator am bient tem p er­
ature which is the tem perature of the a ir m easured
at a distance of %-inch from the regulator co v er.
Check and adjust voltage settin g a s follow s:
1. Insert a te st prod into w iring h arn ess con­
n ector at regulator No. 3 term in al, then connect a
v o ltm eter from the te s t prod to ground.
2. D isconnect negative battery cable from the
battery and connect a %-ohm 25-w att r e s is t o r in
s e r ie s .
NOTE: In the event the battery is partially
discharged, the r e s is to r w ill lim it generator out­
put to 10 am p eres or le s s which is required when
checking and adjusting the voltage settin g.
3. S ecure a th erm om eter c lo s e to regulator
cover to e sta b lish operating tem perature; then with
a ll a c c e s s o r ie s turned off and h arn ess connected
to regulator, sta rt and operate engine at 1500 rpm
for 15 m inutes to esta b lish regulator operating
tem perature.
IMPORTANT: Do not operate engine with bat­
tery disconnected.
4. C ycle the regulator by disconnecting, then
connecting the wiring h arness connector at the
regulator.
5. B ring engine speed up to approxim ately
2500 rpm , note the am bient tem perature and v o lt­
age settin g and com pare with applicable "Tem per­
ature V oltage Chart” in "Specifications" at end of
th is sectio n .
6. Adjust voltage setting for the upper or sh o rt­
ing contacts a s follow s:
a. D isconnect w iring h arn ess connector from
regulator, then rem ove regulator cover and connect
w iring h arn ess connector to regulator.
b. Turn adjusting screw shown in figu re 18,
to adjust the voltage setting.
IMPORTANT: E nsure that spring holder is
against head of adjusting sc r e w . When turning the
sc r e w counterclockw ise, turn until the sc r e w head
i s approxim ately 1 /8 -in c h above the holder, then
p ry holder up against sc r e w head. A lw ays turn
sc r e w clo ck w ise to make final settin g.
7. After adjusting the voltage settin g, cy cle
the regulator by disconnecting, then connecting the
w iring h arn ess connector at the regulator.
8. Operate engine at approxim ately 2500 rpm
and check the voltage settin g. Adjust if n e c e ssa r y .
A lw ays cy c le the regulator (Step 7) b efore reading
the final voltage settin g.
CHEVROLET SERIES 70-90 HEAVY DUTY TRUCK SHOP MANUAL SUPPLEMENT