ENGINE-ELECTRICAL 6Y-11
I
BAT
JUNCTION BLOCK
DELCOTRON
—GRQ
BATTERY
&HJVVWV
0 VA OHM TEST RELAY >
RESISTOR [ 1 d
FUSIBLE
LINK
TO CRANKING
MOTOR
Ik
REGULATOR
VOLTMETER
FUSIBLE LINK
IGN.
SWITCH
Fig.
7c—Voltage Setting Test Connections
NOTE:
Voltage will not greatly exceed 12-1/2
volts until the battery develops a surface charge,
a few minutes generally, unless the battery is
severely discharged or is hot.
If reading is:
a. 12-1/2 volts or more, turn off electrical loads,
stop engine and proceed to Step 7.
b.
Less than 12-1/2 volts, perform "Delcotron Out-
put Test-Voltmeter Method."
(1) Delcotron tests bad—refer to "Service Op-
erations" and repair Delcotron, then repeat
Step 6.
(2) Delcotron tests good—disconnect regulator
connector, remove regulator cover and recon-
nect the connector. Then repeat Step 6 and
turn voltage adjusting screw (fig. 6c) to raise
setting to 12-1/2 volts. On transistor regula-
tor remove pipe plug (fig. 6c), insert screw
driver into slot and turn clockwise one or two
notches to increase setting. Turning counter-
clockwise decreases setting. For each notch
moved, the voltage setting will change ap-
proximately .3 volt. Turn off loads, stop en-
gine and proceed to Step 7. If 12-1/2 volts
cannot be obtained, install a new regulator and
repeat Step 6.
ADJUSTING REGULATOR VOLTAGE
7. Connect a 1/4 ohm-25 watt fixed resistor (purchased
commercially) into the charging circuit at the junc-
tion block as shown in Figure 7c.
NOTE:
Between both leads and the terminal.
8. Run engine at 1500 rpm or above for at least 15
minutes of warm-up, then 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.
If voltage is not within 13.5 to 15.2 volts, leave en-
gine running at 1500 rpm or above and:
a. Disconnect four terminal connector and remove
regulator cover. Then re-connect four terminal
connector and adjust voltage to i4.2 to 14.6.
(Refer to Step 6 and fig. 6c).
b.
Disconnect four terminal connector and reinstall
regulator cover, then reinstall connector.
c. Continue running engine at 1500 rpm for 5-10
minutes to re-establish regulator internal
temperature.
d. Cycle regulator voltage by disconnecting and re-
connecting regulator connector. Read voltage. A
reading between 13.5 and 15.2 indicates a good
regulator.
CAUTION: Be sure four terminal regulator
connector is disconnected when removing or in-
stalling cover. This is to prevent regulator
damage by short circuits.
DELCOTRON OUTPUT TEST
Ammeter Method (Fig. 8c)
1.
Disconnect the battery ground cable at the battery.
2.
Disconnect the red wire at Delcotron battery termi-
nal and connect an ammeter in series between the
wire and terminal.
3.
Connect a voltmeter from battery terminal to a good
ground on the generator.
4.
Disconnect the F-R terminal connector at the
Delcotron.
5. Connect the jumper wire between Delcotron "F" and
battery terminals.
6. Connect the battery ground cable at the battery.
7. Connect an adjustable carbon pile across the battery
posts.
8. Start the engine and slowly bring the speed to 1500
RPM and at the same time adjust the carbon pile
load to hold the voltage at 14 volts.
9. Read the amperage and compare with a specifications
chart.
CHEVROLET CHASSIS SERVICE MANUAL
