Файл: 92FWD_8A.pdf

the wiring harness from the alternator. Refer to Alternator Testing. Do not disconnect test light.

CAUTION: This last test has higher amperage IOD and must be performed before going on with low amperage IOD tests. The higher amperage IOD must be eliminated before hooking up milliamp meter to check for low amperage IOD. If higher amperage IOD has not been eliminated, milliamp meter may be damaged. Most milliamp meters will not handle over one or two amps. Do not hook up meter if test light is glowing brightly. Refer to maximum amperage specifications and instructions supplied with milliamp meter.

After higher amperage IOD has been corrected, low amperage IOD may be checked. The MAXIMUM IOD= 30 MILLIAMPERES.

(5) With test light still connected, connect milliamp meter between battery negative post and negative battery cable (Fig. 19). Do not open any doors or turn on any electrical accessories with the test light disconnected and the milliamp meter connected. Meter may be damaged.

Fig. 19 Low Amperage IOD Test

(6) Disconnect test light. Milliamp meter reading should be less than 30 milliamperes. If low amperage IOD is not within specifications, disconnect:

(a)The 60 way connector at the Engine Controller located outboard of the battery. Refer to Group 8D, Ignition for more information.

(b)The 25 way connectors on the Body Controller if equipped.

(c)The circuits to the clock and radio.

(d) The wiring harness from the alternator. Refer to Alternator Testing.

Check each component until excessive IOD is found. Each time the test light or milliamp meter is disconnected and connected, all electronic timer functions will be activated. Tests must be repeated from

the beginning.

Test light or meter MUST remain connected for all tests.

VEHICLES EQUIPPED WITH ELECTRONIC AUTOMATIC TRANSMISSION, LOAD LEVELING SUSPENSION, OR ALARM SYSTEM

This vehicles will have temporary high IOD of 15 amps or more for up to 65 minutes. This higher IOD can often mask another problem and should be considered when performing IOD testing.

Testing for higher IOD will be the same as in the previous IOD tests. However, certain additional procedures should be followed.

² WITH ALARM SYSTEM: After disconnecting battery and hooking up test light, cycle the key lock on the driver's door to disarm the alarm. The parking lamps should stop flashing.

Also locate the Power Distribution Center. This Center is located in front of the left front strut tower (Fig. 20). Remove the cover from the Center and remove the 50 amp fuse.

Fig. 20 Power Distribution Center

²WITH ELECTRONIC AUTOMATIC TRANSMISSION: If equipped with this option, and high or low IOD is suspected, allow an additional 25 minutes minimum of electronic shut off time.

To defeat the timer, disconnect the 60-way connector on the Transmission Controller. This controller is located on the right inner fender.

²WITH AUTOMATIC LOAD LEVELING SYSTEM: If equipped with this option, and high or low IOD is suspected, allow an additional 65 minutes minimum of electronic shut off time.

To defeat the timer, open the trunk lid, locate the Automatic Load Leveling computer, located inside right rear wheelhouse, and disconnect the 11-way connector. Close the trunk lid.

If equipped with an electrical trunk closing feature, temporarily install a heavy gauge jumper wire between the disconnected negative cable and the nega-

tive battery post. When this jumper is installed the trunk lid should automatically close. Do not disconnect the test light as all electronic timing features will be activated and all IOD tests must be repeated from the beginning.

Remove the temporarily installed jumper wire.

GENERAL INFORMATION

The starting system (Fig. 1) has:

²Ignition switch

²Starter relay (Fig. 2)

²Neutral starting and back-up switch with automatic transmissions

²Clutch pedal mounted starter interlock switch with manual transmissions

²Wiring harness

²Battery

²Starter motor with an integral solenoid

These components form two separate circuits. A high amperage circuit that feeds the starter motor up to 300+ amps, and a control circuit that operates on less than 20 amps.

DIAGNOSTIC PREPARATION

Before going on with starting system diagnostics, verify:

(1)The battery top, posts, and terminals are clean.

(2)The alternator drive belt tension and condition is correct.

(3)The battery state-of-charge is correct.

(4)The battery will pass load test.

(5)The battery cable connections at the starter and engine block are clean and free from corrosion.

(6)The wiring harness connectors and terminals are clean and free from corrosion.

(7)Proper circuit grounding.

(8)Refer to Starter System Diagnostics (Fig. 3).

Fig. 4 Volt Ampere Tester

CAUTION: Ignition system also must be disabled to prevent engine start while performing the following tests.

(1)Connect a volt-ampere tester (Fig. 4) to the battery terminals (Fig. 5). Refer to the operating instructions provided with the tester being used.

(2)Disable ignition system as follows:

Fig. 5 Volt-Ampere Tester Connections

²VEHICLES WITH CONVENTIONAL DISTRIBUTORS: Disconnect the ignition coil cable from the distributor cap. Connect a suitable jumper wire between the coil cable end-terminal and a good body ground (Fig. 6).

²VEHICLES WITH DIRECT IGNITION SYSTEM: Disconnect the ignition coils electrical connector (Fig. 7).

(3)Verify that all lights and accessories are OFF, and the transmission shift selector is in PARK or manual in NEUTRAL. Set parking brake.

Fig. 6 Ground Ignition Coil Cable

Fig. 7 Ignition Coils Electrical Connection

(4) Rotate and hold the ignition switch in the START position. Observe the volt-ampere tester (Fig. 8).

²If voltage reads above 9.6 volts, and amperage draw reads above 250 amps, go to the starter feed circuit resistance test.

²If voltage reads 12.4 volts or greater and amperage reads 0 to 10 amps, go to starter control circuit test.

CAUTION: Do not overheat the starter motor or draw the battery voltage below 9.6 volts during cranking operations.

(5) After the starting system problems have been corrected, verify the battery state of charge and charge battery if necessary. Disconnect all testing equipment and connect ignition coil cable or ignition coil connector. Start the vehicle several times to assure the problem was corrected.

STARTER FEED CIRCUIT RESISTANCE TEST

Before going on with this operation, review Diagnostic Preparation and Starter Feed Circuit Tests. The following operation will require a voltmeter, accurate to 1/10 of a volt.

CAUTION: Ignition system also must be disabled to prevent engine start while performing the following tests.

(1)Disable ignition system as follows:

²VEHICLES WITH CONVENTIONAL DISTRIBUTORS: Disconnect the ignition coil cable from the distributor cap. Connect a suitable jumper wire between the coil cable end-terminal and a good body ground (Fig. 6).

²VEHICLES WITH DIRECT IGNITION SYSTEM: Disconnect the ignition coils electrical connector (Fig. 7).

(2)With all wiring harnesses and components properly connected, perform the following:

(a)Connect the negative lead of the voltmeter to the negative battery post, and positive lead to the negative battery cable clamp (Fig. 9). Rotate and