1988 JEEP CHEROKEE engine

maintaining 13 volts or more.
3) Output must be within 15 amps of rated output stamped on
alternator. If output is not within 15 amps of rated output, replace
alternator.
SI SERIES
Overcharged Or Undercharged Battery
1) If an overcharging condition is suspected, attach a
voltmeter across battery terminals. Run engine at a moderate speed
with all accessories off. If voltmeter reads 15.5 volts or more,
remove alternator for repair.
2) If an undercharging condition is suspected, turn ignition
on. Connect a voltmeter from alternator "BAT" terminal to ground.
Voltmeter should read 12 volts. Connect voltmeter between No. 1
terminal and ground. Voltmeter should read one volt or more.
3) Connect voltmeter between No. 2 terminal and ground.
Voltmeter should read 12 volts. A zero reading on any connection
indicates an open between connection and battery. Opens in the No. 2
lead may be between terminals at the crimp between harness wire and
terminal, or in wire.
Alternator Output Test
1) Connect an ammeter in circuit at "BAT" terminal of
alternator. Turn on all available accessories. Connect a carbon pile
across battery. Operate engine at 2000 RPM and adjust carbon pile as
required to obtain maximum current output.
2) Ampere output must be within 10 amps of rated output. If
output is not within 10 amps of rated output, ground field winding by
inserting a screwdriver into test hole. Repeat step 1).
3) If output is increases to within 10 amps of rated output
with field grounded, regulator is defective. If output remains below
10 amps of rated output, check field winding, diode trio, rectifier
bridge, and stator.
CAUTION: Tab is within 3/4" of casting surface. DO NOT force tool
beyond 1" into end frame. If test hole is not accessible,
proceed to BENCH TESTING.
BENCH TESTING
NOTE: There are no internal checks for CS series alternators.
SI SERIES
Rotor Field Winding Test
1) To check for grounds, attach ohmmeter leads to shaft and
slip ring (each ring in turn). If reading is not infinity, replace
rotor.
2) To test for open field, attach ohmmeter leads to each slip
ring. Resistance should measure about 2.4
2.8 ohms on 12SI series, or
1.72.1 ohms on 17SI series. If not, replace rotor.

Fig. 7: Exploded View of Model 17SI Alternator
Courtesy of General Motors Corp.
SPECIFICATIONS
ALTERNATOR OUTPUT FOR CS SERIES








\









\









\









\









\









\

Stamped Rating Amps @ 14v Engine RPM
85 .................. 30 ..................... 1600
100 ................. 36 ..................... 1600
105 ................. 42 ..................... 1600









\









\









\









\









\









\

ALTERNATOR OUTPUT FOR SI SERIES








\









\









\









\









\









\

Stamped Rating Amps @ 14v Engine RPM
66 .................. 23 ..................... 1600
78 .................. 30 ..................... 1600
94 .................. 30 ..................... 1600
120 ................. 50 ..................... 1600









\









\









\









\









\









\

Fig. 89: Test 6E - 8-Way Black Connector Cavity "H" (Cherokee)
Fig. 90: Test 6E - TCU 32-Way Connector (Cavity 8)
TEST 7A - CODE 705 - TPS CIRCUIT
NOTE: Perform TEST 1A - VERIFICATION OF THE COMPLAINT
before proceeding.
NOTE: On Cherokee, engine diagnostic connector is located at left
side of engine compartment, near engine controller. Engine
diagnostic connector is a 6-terminal connector.

Fig. 97: Test 7A - Code 705, View of TPS Connector
Fig. 98: Test 7A - Location of Engine Control Connector (Cherokee)

Fig. 99: Test 7A - View of Engine Control Connector (Cavity 22)
TEST 8A - CODE 706 - BRAKE SWITCH CIRCUIT
NOTE: Perform TEST 1A - VERIFICATION OF THE COMPLAINT
before proceeding.

Fig. 106: Test 8A - View of Engine Controller Connector (Cavity 29)
Fig. 107: Test 8A - TCU 32-Way Connector (Cavity 10, Cherokee)
Fig. 108: Test 8A - Location of Brake Switch Connector

Fig. 113: Test 7A - Location of Engine Control Connector (Cherokee)
Fig. 114: Test 8B - TCU 32-Way Connector (Cavity 10, Cherokee)
TEST 9A - WRONG TCU
NOTE: Perform TEST 1A - VERIFICATION OF THE COMPLAINT
before proceeding.
NOTE: The AW-4 is used only on 4.0L. In earlier years, it was