Chevrolet CHEVY VAN G10 SERIES Service Manual page 225

ENGINE ELEC TR IC A L 6Y-14
Test as Follows:
1. D isconnect conn ector from regulator and tu rn ignition
switch to " O N " . C onnect a test lam p from connector
term inal " 4 " to ground (Fig.
a. Lam p fails to glow — check for faulty bulb, socket or
open circuit betw een sw itch and regulator con­
nector. Repair as needed.
b. Light goes o n — failure is in regulator, D elcotron, or
wire betw een " F " term inals on regulator and Delco­
tro n . Go to S tep 2.
2. Disconnect lam p lead
betw een connector " F " and " 4 " term inals (Fig.
2
), and note lamp:
a. Test lam p glows—problem is in regulator. An open
circuit in regulator o r relay is stuck closed. See
" Service O perations" for repair.
b. Fails to glow —problem is in wire betw een " F "
term inals on generator and regulator or in field
windings. Go to S tep 3.
3. D isconnect test lam p at connector " F " term inal and
connect to " F " term inal on D elcotron (Fig.
and n ote lamp:
a. Lam p glows— an open circuit in wire betw een " F "
term inals—correct as needed.
b. Fails to glow —D elcotron field has open circuit see
" Service O perations" to repair.
W IR IN G HARNESS
C O N N E C T O R
Fig. 7c—Testing Field Relay
6
c, Step 1) and no te lamp.
at ground end and connect
6
c, Step
6
c, Step 3),
N O T E : This test lamp procedure may be used on
lamp type circuits and on am meter circuits.
If Lamp Fails to Go O ut, or if A m m eter Shows Discharge
the Possible Causes are:
1. Loose drive b e lt— adjust as necessary.
2. F aulty field re la y -(se e relay test and adjustm ent).
3. Defective D elcotron— (see D elcotron o u tp u t test).
4. At norm al idle— parallel resistance wire open (See Resist­
ance Test). A m m eter m odels the initial field excitation
wire to " ACC" term inal is open.
5. Switch o ff— positive diode shorted (See Diode T est).
Field Circuit Resistance Wire Cnecks
The resistance wire is an integral part o f th e ignition
harness. However, the resistance wire is n ot solderable; it m ust
be spliced w ith a crim p-type connector. It is rated at 10 ohms,
6.25 w atts m inim um .
The check for an open resistor or field excitation wire
(connected to the ignition sw itch " ACC" term inal) is as
follows:
1. C onnect a test lam p from the wiring harness connector
term inal "4 " to ground as show n in Figure
2. T urn th e ignition sw itch to th e " ON" position and note
test bulb.
a. Test lam p glows— resistance is O.K.
b. Test lam p does n ot glow— th e resistor is open
circuited— note also th a t dash lam p does n ot glow
during this test because series resistance o f the
bulbs causes amperage to be too low.
6
c (Step 1).
2
C H E V Y V A N SH O P M A N U A L