Dodge RAM TRUCK 1500 1995 Service Manual page 354

B R
BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 3A - 21
PREPARATION
(1) Before starting test make sure vehicle has a
fully-charged battery. See Battery in this group for
more information.
(2) Disconnect negative cable from battery.
(3) Disconnect generator output wire at the gener­
ator battery output terminal.
(4) Connect a 0-150 ampere scale DC ammeter
(Fig. 23). Install in series between generator battery
output terminal and disconnected generator output
wire. Connect positive lead to generator battery out­
put terminal and negative lead to disconnected gen­
erator output wire.
(5) Connect positive lead of a test voltmeter (range
0-18 volts minimum) to generator battery output ter­
minal.
(6) Connect negative lead of test voltmeter to a
good ground.
(7) Connect an engine tachometer, then connect
battery negative cable to battery.
(8) Connect a variable carbon pile rheostat be­
tween battery terminals. Be sure carbon pile is in
OPEN or OFF position before connecting leads. See
Load Test in this group for instructions.
(9) Connect one end of a jumper wire to ground
and with other end probe green K20 field wire at
back of generator (Fig. 23). This will generate a DTC.
CAUTION: Do not connect green/orange A142 field
wire to ground. Refer to Group
grams for more information.
8W - Wiring Dia-
TEST
(1) Start engine. Immediately after starting, re­
duce engine speed to idle.
(2) Adjust carbon pile and engine speed in incre­
ments until a speed of 1250 rpm and voltmeter read­
ing of 15 volts is obtained.
CAUTION: Do not allow voltage meter to read above
16 volts.
(3) The ammeter reading must be within limits
shown in Generator Output Voltage Specifications.
RESULTS
(1) If reading is less than specified and generator
output wire resistance is not excessive, generator
should be replaced. Refer to Group 8B - Battery/
Starter/Generator Service.
(2) After current output test is completed, reduce
engine speed, turn OFF carbon pile and turn OFF ig­
nition switch. * •
(3) Disconnect negative cable from battery.
(4) Remove test ammeter, voltmeter, tachometer
and carbon pile.
(5) Remove jumper wire (Fig. 23).
(6) Connect generator output wire to generator
battery output terminal. Tighten nut to 8.5±1.5 N-m
(75±15 in. lbs.).
(7) Connect negative cable to battery.
(8) Use DRB scan tool to erase DTC.
CASE GROUND
BATTERY
VOLTAGE
TO POWERTRAIN
CONTROL MODULE
TERMINAL —
51
A142
AUTO
SHUTDOWN
RELAY
3^
10 AMP FUSE
30 AMP FUSE
4
IGNITION SWITCH
POWER
DISTRIBUTION
CENTER
GROUND
POWERTRAIN
CONTROL MODULE
DISCONNECTED
GENERATOR
GROUND
ACC • OFF
frtTART%UNl
Bl
a 1 ^ 5 F F
I k ^ N
CARBON PILE
RHEOSTAT
IE
BATTERY / q ]
CHASSIS '
GROUND
J948A-18
Fig. 23 Generator Current Output Test - Typical