1993 CHEVROLET DYNASTY air condition

sends the message to the Engine Controller. The En-
gine Controller turns on the fan through the fan re-
lay. See Wiring Diagrams Manual for circuity and
diagnostics provided.Switching through the Engine Controller provides
fan control for the following conditions.
² The fan will not run during cranking until the en-
gine starts no matter what the coolant temperature
is.
² Fan will run when the air conditioning clutch is
engaged and low pressure cutout switch is closed.
² For 4 cylinder application the fan will run at ve-
hicle speeds above about 40 mph only if coolant tem-
perature reaches 110ÉC (230ÉF). It will turn off when
the temperature drops to 104ÉC (220ÉF). At speeds
below 40 mph the fan switches on at 102ÉC (215ÉF)
and off at 93ÉC (200ÉF).
² This is to help prevent steaming. The fan will run
only below 16ÉC (60ÉF) ambient. Between 38ÉC
(100ÉF) to 97ÉC (195ÉF) coolant temperature, at idle
and then only for three minutes.
RADIATOR FAN CONTROLÐAC/AY BODY V-6 ONLY
For this application, fan control is accomplished
based on coolant temperature, and on A/C head pres-
sure. These vehicles receive the variable displace-
ment compressor. The fan will go on when;
² Coolant temperature reaches 102ÉC (215ÉF) and off
at 93.4ÉC (200ÉF) regardless of vehicle speed.
² When the head pressure reaches 1516.9 kPa (220
psi) and turn off when the pressure reaches 1103 kPa
(160 psi).
TEMPERATURE GAUGE INDICATION
At idle the temperature gauge will rise slowly to
about 5/8 gauge travel. The fan will come on and the
gauge will drop to about 1/2 gauge travel, this is nor-
mal.
ELECTRIC FAN MOTOR
To check out the electric fan motor, disconnect the
fan motor wire connector and connect it with #14
gauge wires to a good 12-volt battery observing cor-
rect polarity per (Fig. 14). If the fan runs normally,
the motor is functioning properly. If not, replace fan
module using the removal and installation instruc-
tions contained in the Fan Section. If the motor is
noticeably overheated (i.e.; wire insulation melted,
motor charred) the system voltage may be too high.
Check charging system, see Group 8A, Battery/Start-
ing/Charging System Diagnostics.
ELECTRIC FAN MOTOR TEST
Equipment required
² Diagnostic Tool DRB II or equivalent
² Volt/Ohm Meter
² Wiring Diagram Manual (1) Run the engine to normal operating tempera-
ture. (2) Check wiring connector in C25, C9, and C26 for
proper engagement, see Wiring Diagram Manual (3) Using a diagnostic tool, plugged into the diag-
nostic connector rearward of the battery, check the
On-Board Diagnostics (OBD) in the Engine Control-
ler for fault codes, see Group 14, Fuel Injection for
instructions. (4) If fault code 88-12-35-55 is detected, proceed to
Step 5. (5) With the ignition switch in the run position,
test for battery voltage (single pin connector) at the
fan relay. Voltage reading OK, proceed to Step 6a.
Voltage at 0-1 volt, proceed to Step 6b. 6(a) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at cavity 31 of the 60-way
connector (Fig. 15). Voltage reading OK and female
terminal is not damaged, replace the Engine Control-
ler. Voltage reading 0, repair open or short in C27
circuit. (b) With the ignition off, disconnect the 60-way
connector from the Engine Controller (outboard of
battery) and return the ignition to the run position.
Test for battery voltage at the single pin connector
at the fan relay. Voltage reading OK, replace the
Engine Controller. Voltage reading 0-1 volt, pro-
ceed to Step 7.
(7) With ignition in the run position, test for bat-
tery voltage at the wire (C27) in the 3-way connector
of the fan relay. Voltage reading OK, replace the fan
relay. Voltage reading 0, repair open or short in C27
circuit. (8) Turn ignition off, connect the 60-way connector
at the Engine Controller and test the system.
Fig. 14 Electric Fan MotorÐTypical
7 - 22 COOLING SYSTEM Ä

ACCESSORY DRIVE BELTS INDEX
page page
2.2/2.5L Engine Belts Remove/Install-Adjust .... 24
3.0L Engine Belts Remove/Install and Adjust .... 25
3.3/3.8L and Turbo III Engine Accessory Drive Belt Remove and Install
..................... 26
General Information ....................... 24
GENERAL INFORMATION
PROPER BELT TENSION
Satisfactory performance of the belt driven accesso-
ries depends on belt condition (Fig. 1) and proper belt
tension. Two tensioning methods are given in order
of preference:
² Belt tension gauge method.
² Torque equivalent method.
The belt tension gauge method is usually restricted
to use after the vehicle has been raised on a hoist
and the splash shield has been removed.
BELT TENSION GAUGE METHOD Use belt tensioning Special Tool Kit C-4162 for:
² For conventional belts and Poly-V belts.
Adjust the belt tension for a NeworUsed belt as
prescribed in the Belt Tension Chart.
TORQUE EQUIVALENT METHOD Adjustable accessory brackets provided with a
13mm (1/2 in.) square hole for a torque wrench can
use an equivalent torque value for belt adjustment. Equivalent torque values for adjusting these acces-
sory drive belts are specified on the Belt Tension
Charts .
2.2/2.5L ENGINE BELTS REMOVE/INSTALL-
ADJUST
AIR CONDITIONING COMPRESSOR
(1) Loosen the idler bracket pivot screw A and
locking screws B (Fig. 2) to remove and install belt
and/or adjust belt tension.
ACCESSORY DRIVE BELTS DIAGNOSIS
Fig. 1 Drive Belt Inspection
7 - 24 COOLING SYSTEM Ä

(2) Adjust belt tension by applying torque to
square hole C on idler bracket. Adjust tension to
specification given in Belt Tension Chart. (3) Tighten in order, first, locking screws B then
pivot screw A to 54 N Im (40 ft. lbs.).
POWER STEERING PUMPÐS TYPE
(1) From on top of the vehicle loosen locking screw G.
(2) From under the vehicle loosen the pivot screw
and pivot nut H . (3) After installing a new belt adjust belt tension
with 1/2 in. breaker bar installed in adjusting
bracket. See tension specification in chart. (4) Tighten locking screw G to 54 N Im (40 ft. lbs.).
(5) Tighten pivot screw H and the pivot nut to 54
N Im (40 ft. lbs.)
GENERATOR BELT
(1) Loosen T-Bolt locking nut E and adjusting
screw F to remove and install Poly V belt and/or ad-
just belt tension. (2) Tighten adjusting screw F to adjust belt tension
to specification shown in Belt Tension Chart. (3) Tighten T-Bolt locking nut E to 54 N Im (40 ft.
lbs.).
3.0L ENGINE BELTS REMOVE/INSTALL AND
ADJUST
AIR CONDITIONING BELT
To remove and install the air conditioning com-
pressor drive belt, first loosen the idler pulley lock
nut, then turn the adjusting screw to raise or lower
the idler pulley (Figs. 3 and 4).
To adjust the air conditioning drive belt, loosen
the idler pulley nut (Fig. 3) and adjust belt tension
Fig. 2 Accessory Drive BeltsÐ2.2 and 2.5L Engines
Fig. 3 Accessory Drive BeltsÐ3.0L Engine
Ä COOLING SYSTEM 7 - 25

by tightening adjusting screw (Figs. 3 and 4 ).
Tighten pulley nut to 54 N Im (40 ft. lbs.) after ad-
justment.
GENERATOR/POWER STEERING PUMP BELT
The Poly-V generator/power steering pump belt is
provided with a dynamic tensioner (Fig. 5) to main-
tain proper belt tension. To remove or install this
belt, Release tension by rotating the tensioner clock-
wise
3.3/3.8L AND TURBO III ENGINE ACCESSORY
DRIVE BELT REMOVE AND INSTALL
GENERATOR, POWER STEERING PUMP, AIR
CONDITIONING COMPRESSOR AND WATER
PUMP DRIVE BELT The Poly-V Drive belt is provided with a dynamic
tensioner (Figs. 7 and 8) to maintain proper belt ten-
sion. To remove or install this belt. (1) Raise vehicle on hoist.
(2) Remove right front splash shield.
(3) Release tension by rotating the tensioner clock-
wise (Figs. 7 and 8). (4) Reverse above procedure to install.
Fig. 5 Release Belt Tensioner
Fig. 6 Belt Tension Chart
Fig. 4 Air Conditioning Belt Idler
7 - 26 COOLING SYSTEM Ä

relay to starter solenoid for loose or corroded connec-
tions. Particularly at starter terminals.
² Repeat test. If engine still fails to crank properly,
trouble is within starter or starter mounted solenoid,
and it must be removed for repairs. Refer to Group
8B, Battery/Starter/Generator Service, Starter re-
placement.
STARTER RELAY TEST
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN PARK OR NEUTRAL WITH THE
PARKING BRAKE APPLIED
(1) Verify battery condition. Battery must be in
good condition with a full charge before performing
any starter tests. Refer to Battery Tests. (2) Perform the preceding starter solenoid tests
BEFORE performing starter relay tests. Refer to
Starter Solenoid Test. (3) Locate and remove the starter relay. For
starter relay locations, refer to Starter Solenoid Test
(Fig. 13 or 14). (4) After the starter relay has been located and re-
moved, refer to Starter Relay Tests (Fig. 15).
NEUTRAL STARTING AND BACK-UP SWITCH
AUTOMATIC TRANSMISSION ONLY
For electrical diagnostics, when checking starter
circuits, refer to Starter Relay Tests (Fig. 15). For replacement of switch, refer to Group 21, Tran-
saxle, Neutral Starting and Switch Replacement.
STARTER INTERLOCK SWITCHÐCLUTCH PEDAL MOUNTED
MANUAL TRANSMISSION ONLY
For electrical diagnostics, refer to the Starter Relay
Tests. For replacement and/or adjustment of the switch,
refer to Group 6, Manual Transaxle Clutch, Manual
Transaxle Starter Interlock Switch.
IGNITION SWITCH TEST
After testing the starter solenoid and relay, test ig-
nition switch and wiring. Refer to Group 8D, Ignition
Systems, or the Front Wheel Drive Car Wiring Dia-
grams Service Manual. Check all wiring for opens or
shorts, and all connectors for being loose or corroded.
BENCH TESTING STARTER SOLENOID
(1) Disconnect field coil wire from field coil termi-
nal (Fig. 16 or 17). (2) Check for continuity between solenoid terminal
and field coil terminal with a continuity tester. Con-
tinuity should be detected (Fig. 18 or 19). (3) Check for continuity between solenoid terminal
and solenoid housing (Fig. 20 or 21). Continuity
should be detected. If continuity is detected, solenoid
is good. (4) If continuity is not detected in either test, sole-
noid has an open circuit and is defective. If equipped
with:
² BOSCH STARTER: Replace the solenoid.
² NIPPONDENSO STARTER: Replace the starter
assembly.
8A - 16 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS Ä

GENERATOR INDEX
page page
General Information ........................ 9
Generator ReplacementÐ2.2L Turbo Engine (With 16 Valve Cylinder Head) ............. 10 Generator ReplacementÐ2.2L/2.5L Engine
...... 9
Generator ReplacementÐ3.0L Engine ......... 10
Generator ReplacementÐ3.3L/3.8L Engine ..... 11
GENERAL INFORMATION
This section will cover generator removal and instal-
lation only. Information covering generator on-vehicle
testing and diagnosis can be found in Group 8A,
Battery/Starting/Charging Systems Diagnostics. To
identify the generator, refer to the Generator Specifi-
cation chart at the rear of this section. These generators are not intended to be disas-
sembled for service. It must be replaced as an
assembly.
GENERATOR REPLACEMENTÐ2.2L/2.5L ENGINE
Removal and repositioning of A/C compressor (with-
out disconnecting refrigerant lines) is necessary on
some models to gain access to generator. (1) Disconnect battery negative cable (Fig. 1).
(2) If Equipped With Air Conditioning:
(a) Remove the A/C drive belt. Refer to Group 7,
Cooling System. (b) Remove the four bolts retaining the A/C com-
pressor to the mounting bracket (Fig. 2). (c) Without disconnecting the A/C refrigerant
lines, position the A/C compressor to allow generator
removal.
WARNING: THE A/C REFRIGERANT SYSTEM IS UN-
DER PRESSURE EVEN WHEN THE ENGINE IS OFF.
REFER TO THE SAFETY PRECAUTIONS AND WARN-
INGS SECTION IN HEATING AND A/C, GROUP 24,
BEFORE PERFORMING ANY SERVICE OPERATION. (3) Remove the generator drive belt. Refer to Group
7, Cooling System. (4) Remove the two generator mounting bolts (Fig.
3) and position the generator to gain access to all the
wire connectors. If equipped with:
² BOSCH GENERATOR: Remove B+ terminal nut,
field terminal nuts, and ground harness hold down
nuts (Fig. 4). Remove wire connector assembly.
² NIPPONDENSO GENERATOR: Remove nuts
from field terminals, ground terminal, wire harness
Fig. 1 Remove Battery Negative (-) Cable
Fig. 2 A/C Compressor ReplacementÐ2.2 L/2.5 L Engine
Fig. 3 Remove/Install Generator
Ä BATTERY/STARTER/GENERATOR SERVICE 8B - 9

and B+ terminal (Fig. 5). B+ terminal nut must be
removed last to prevent damage to terminal insula-
tor. (5) Remove the generator from the vehicle.
(6) For installation, reverse above procedures.
Tighten all fasteners to the proper torque. Refer to
the Torque Specifications chart at the rear of this
group.
GENERATOR REPLACEMENTÐ2.2L TURBO
ENGINE (WITH 16 VALVE CYLINDER HEAD)
(1) Disconnect battery NEGATIVE cable (Fig. 1).
(2) Remove generator/air conditioning drive belt.
Refer to Group 7, Cooling System. (3) Remove the bolts retaining the A/C compressor
to the mounting bracket. (4) Without disconnecting the A/C refrigerant
lines, position the A/C compressor to allow generator
removal. WARNING: THE A/C REFRIGERANT SYSTEM IS UN-
DER PRESSURE EVEN WHEN THE ENGINE IS OFF.
REFER TO THE SAFETY PRECAUTIONS AND
WARNINGS SECTION IN HEATING AND A/C,
GROUP 24, BEFORE PERFORMING ANY SERVICE
OPERATION.
(5) Remove the generator mounting bracket bolts
and separate generator from mounting bracket (Fig.
6).
(6) Remove the B+ terminal nut, field terminal
nuts, and ground/wire harness hold-down nuts. Re-
move wire connectors. (7) Remove the generator from the vehicle.
(8) For installation, reverse above procedures.
Tighten all fasteners to the proper torque. Refer to
the Torque Specifications chart at the rear of this
group.
GENERATOR REPLACEMENTÐ3.0L ENGINE
(1) Disconnect battery negative cable (Fig. 1).
(2) Remove generator drive belt. Refer to Group 7,
Cooling System. (3) Remove the generator mounting bolts and sep-
arate the generator from the mounting bracket (Fig.
7). (4) Remove the B+ terminal nut, field terminal
nuts, and ground/wire harness hold-down nuts. Re-
move wire connectors. (5) Remove the generator from the vehicle.
Fig. 4 Remove or Install Wire Connector AssemblyÐBosch Generator
Fig. 5 Remove or Install Wire ConnectorAssemblyÐNippondenso Generator
Fig. 6 Generator MountingÐ2.2 L Turbo Engine With 16 Valve Cylinder Head
8B - 10 BATTERY/STARTER/GENERATOR SERVICE Ä

When testing secondary cables for punctures and
cracks with an oscilloscope follow the equipment
manufacturers instructions. If an oscilloscope is not available, secondary cables
can be tested as follows:
CAUTION: Do not leave any one spark plug cable
disconnected any longer than necessary during test-
ing. Excessive heat could damage the catalytic con-
verter. Total test time must not exceed ten minutes.
(a) With the engine not running, connect one end
of a test probe to a good ground. Use a probe made of
insulated wire with insulated alligator clips on each
end. (b) With engine running, move test probe along
entire length of all cables (approximately 0 to 1/8
inch gap). If punctures or cracks are present there
will be a noticeable spark jump from the faulty area
to the probe. Check the coil cable the same way.
Replace cracked, leaking or faulty cables.
When replacing cables, install the new high
tension cable and nipple assembly over cap or
coil tower. When entering the terminal into the
tower, push lightly, then pinch the large diam-
eter of nipple to release air trapped between the
nipple and tower. Continue pushing on the cable
and nipple until cables are properly seated in the
cap towers. A snap should be heard as terminal
goes into place. Use the same procedure to install cable in coil tower.
Wipe the spark plug insulator clean before reinstalling
cable and cover. Use the following procedure when removing the high
tension cable from the spark plug. First, remove the
cable from the retaining bracket. Then grasp the ter-
minal as close as possible to the spark plug. Rotate the
cover and pull the cable straight back. Pulling on the
cable itself will damage the conductor and termi-
nal connection. Do not use pliers and do not pull
the cable at an angle. Doing so will damage the
insulation, cable terminal or the spark plug in-
sulator. Wipe spark plug insulator clean before
reinstalling cable and cover. Resistance type cable is identified by the words
Electronic Suppression printed on the cable jacket.
Use an ohmmeter to check resistance type cable for
open circuits, loose terminals or high resistance as
follows: (a) Remove cable from spark plug.
(b) Lift distributor cap from distributor with
cables intact. Do not remove cables from cap. The
cables must be removed from the spark plugs. (c) Connect the ohmmeter between spark plug end
terminal and the corresponding electrode inside the
cap, make sure ohmmeter probes are in good contact.
Resistance should be within tolerance shown in the cable resistance chart. If resistance is
not within tolerance, remove cable at cap tower
and check the cable. If resistance is still not within
tolerance, replace cable assembly. Test all spark
plug cables in same manner.
To test coil to distributor cap high tension cable,
remove distributor cap with the cable intact. Do not
remove cable from the cap. Connect the ohmmeter
between center contact in the cap and remove the ca-
ble at coil tower and check cable resistance. If resis-
tance is not within tolerance, replace the cable.
SPARK PLUGS
Resistor spark plugs are used in all engines and
have resistance values of 6,000 to 20,000 ohms when
checked with at least a 1000 volt tester. Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. An iso-
lated plug displaying an abnormal condition indi-
cates that a problem exists in the corresponding
cylinder. Replace spark plugs at the intervals recom-
mended in Group O. Undamaged low milage spark plugs can be cleaned
and reused. Refer to the Spark Plug Condition sec-
tion of this group. After cleaning, file the center elec-
trode flat with a small point file or jewelers file.
Adjust the gap between the electrodes (Fig. 6) to the
dimensions specified in the chart at the end of this
section. Always tighten spark plugs to the specified torque.
Over tightening can cause distortion and change
spark plug gap. Tighten spark plugs to 28 N Im (20 ft.
lbs.) torque.
SPARK PLUG CONDITION
NORMAL OPERATING CONDITIONS
The few deposits present will be probably light tan
or slightly gray in color with most grades of commer-
cial gasoline (Fig. 7). There will not be evidence of
electrode burning. Gap growth will not average more
than approximately 0.025 mm (.001 in) per 1600 km
(1000 miles) of operation. Spark plugs that have nor-
mal wear can usually be cleaned, have the electrodes
filed and regapped, and then reinstalled. Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
CABLE RESISTANCE CHART
Ä IGNITION SYSTEMS 8D - 3