Chevrolet CHEVY VAN G10 SERIES Service Manual page 223

ENG INE E LEC TR IC A L 6Y-12
6
. T urn on high-beam headlights and heater blow er m o to r
to high speed, run engine at or above 1500 rpm (for a
few m inutes, if necessary) an d read the voltage on m eter.
N O T E : Voltage w ill
volts until the battery developes a surface charge, a
few minutes generally, unless the battery is severely
discharged or is hot.
If reading is:
1 2 1/2
a. - volts or m ore, tu rn o ff electrical loads, stop
engine and proceed to Step 7.
b. Less th a n 12-1/2 volts, perform " D elcotron O utput
T e st-A m m e te r M ethod."
(1 ) D elcotron tests b ad — refer to " The Overhaul
M anual" and repair D elcotron, th e n repeat
6
Step .
(2 ) D elcotron
connector, remove regulator cover and recon-
Fig. 5c—A m m eter Method O u tpu t Test Connection
Fig. 4 c —Voltage Setting Test Connection
not greatly exceed 1 2 -1 /2
tests good— disconnect regulator
nect the connector. Then repeat S tep
tu rn voltage adjusting screw (Fig. 3c) to raise
setting to 12-1/2 volts. T urn o ff loads, stop
engine and proceed to Step 7. If 12-1/2 volts
cannot be obtained, install a new regulator and
repeat Step
Adjusting Regulator Voltage
7. Connect a 1/4 ohm -25 w att fixed resistor (purchased
com m ercially) into th e charging circuit at th e ju n ctio n
block as show n in Figure 4c.
N O T E : Between both leads and the term inal.
8
. Run engine at 1500 rpm or above for at least 15 m inutes
o f warm-up, th en cycle regulator voltage control (by
disconnecting and re-connecting regulator connector) and
read voltage.
If voltage is 13.5 to 15.2, the regulator is okay.
a. D isconnect four term inal connector and reinstall
regulator cover. Then re-connect four term inal co n ­
nector and adjust voltage to 14.2 and 14.6 (Refer to
6
Step and Fig. 3c).
b. D isconnect four term inal connector and reinstall
regulator cover, th en reinstall connector.
c. C ontinue running engine at 1500 rpm for 5-10
m in u t e s to r e - e s t a b l i s h
tem perature.
d. Cycle regulator voltage by disconnecting and re­
connecting regulator connector. Read voltage. A
reading betw een 13.5 and 15.2 indicates a good
regulator.
C A U T IO N : Be sure fo u r term inal regulator con­
nector is disconnected when removing or installing
cover. This is to prevent regulator damage by short
circuits.
6
.
r e g u la to r internal
C H E V Y V A N SH O P M A N U A L
6
and