Chevrolet 10 Series 1970 Service Manual page 406

ENGINE-ELECTRICAL 6Y-14
W IR IN G HARNESS
C O N N E C T O R
F ig . 10c—Testing F ie ld Relay
3. Turn ignition switch off.
4. Slowly d ecrease resistan ce and note closing voltage
o f the re la y. Adjust by bending heel iron in the
manner illu strated in F igu re 12c.
O ther Harness Checks
Other w ire s in the charging system harness need be
checked fo r continuity by use o f an ohm m eter o r a test
light (12 V olt). Connect the test lamp so the w ire in
question is in s e rie s in the test circu it.
Full Transistor Regulator Test Procedure
6 .6 " G enerator System— 13 0 A M P (Fig. 13c)
The full tran sistor test p roced u res are made fo r the
purpose o f isolating the unit that is causing the charging
system malfunction. L ik e any other system , we make a
continuity check, voltage
sistance test.
In o rd e r to e a sily make these tests, it is necessary to
use an adapter at the
N otice that the adapter shown in the illu stration s has
three d iffe ren t length test leads. This is only fo r pur­
poses o f differen tiatin g during this p rogram .
M a k e The Test as Follows:
1. Make usual visual checks.
2. Make the battery light load test.
3. Make a com plete charging system test as follow s:
setting test, and c ircu it r e ­
regu lator harness connector.
W IR IN G
C O N N E C T O R
F ig . 11c—F ie ld R elay C lo sin g V o lta g e Test
a. T e s t the fie ld relay.
b. Check the fie ld circu it.
c. Check gen erator output.
d. Check circu it resistance.
e. T e s t and adjust the voltage setting.
To Check The Field Relay
1. Connect a vo ltm eter at test adapter as shown in
Figu re 14c, P a rt 1.
2. Make sure the switch is off, then read voltm eter.
F ig . 12c—A d ju s tin g F ie ld R elay C lo sin g V o lta g e
H A R N E S S
(Same as on any other)
CHEVROLET TRUCK SERVICE MANUAL