Chevrolet 10 Series 1970 Service Manual page 403

(1) D elcotron tests bad - r e fe r to " S ervice Op­
eration s" and re p a ir D elcotron, then repeat
Step 6.
(2) D elcotron tests good - disconnect regu lator
connector, rem ove regu lator cover and r e ­
connect the connector.
and turn voltage adjusting screw (fig . 5c) to
ra is e setting to 12 1/2 v olts. On tra n sistor
regu lator rem ove pipe plug (fig . 5c), insert
screw d r iv e r into slot and turn clockw ise one
o r two notches to in crease setting. Turning
coun ter-clock w ise d e c rea ses
each notch m oved, the voltage
change approxim ately .3 volt. Turn o ff loads,
stop engine and p roceed to Step 7. If 12 1/2
vo lts cannot be obtained, install a new regu ­
lato r and repeat Step 6.
F ig . 7 c —A m m eter M e th o d O u tp u t Test C o n n e c tio n
F ig . 6 c —V o lta g e S e ttin g Test C o n n e ctio n
ADJUSTING REGULATOR VOLTAGE
Then repeat Step 6
setting. For
setting w ill
SYSTEM C O M PO NENT TESTS
Delcotron O utput Test
Am m eter M ethod (Fig. 7c)
Q
d
I___ ___
7. Connect a 1/4 oh m -25 watt fixed r e s is to r (purchased
com m ercia lly ) into the charging circu it at horn rela y
junction block as shown in Figure 6c.
NOTE: Between both leads and the term in al.
8„ Run engine at 1500 rpm or above fo r at lea st 15
minutes of w arm -up, then cycle
control (by disconnecting and re-con n ectin g regu la ­
to r connector) and read voltage.
If voltage is 13.5 to 15.2, the regu la tor is okay.
a. Disconnect four term in al connector and rem ove
regu lator c o v e r. Then re-con n ect four term in al
connector and adjust voltage to 14.2 and 14.6
(R e fe r to Step 6 and fig. 5c).
b. Disconnect four term in al connector and rein sta ll
regu lator cover, then rein sta ll connector.
c. Continue running engine at 1500 rpm fo r 5-10
minutes to re -es ta b lish
tem perature.
d. C ycle regu la tor voltage
re-con n ectin g regu la tor connector. Read voltage.
A reading between
good regu lator.
CAUTIO N: Be sure
connector is disconnected when rem ovin g o r in ­
stalling c o v e r. T h is
damage by short c ircu its.
1. Disconnect the battery ground cable at the battery.
2. Disconnect the red w ire at D elcotron battery t e r ­
minal and connect an am m eter in s e rie s between
the w ire and term in al.
3. Connect a v o ltm e ter from battery term in al to a good
ground on the gen erator.
ENGINE-ELECTRICAL 6Y-11
regu lator voltage
r e g u l a t o r internal
by disconnecting a n d
13.5 and 15.2 indicates a
four term in al regu lator
is to prevent regu lator
CHEVROLET TRUCK SERVICE MANUAL