Horn Test
HORN1. Disconnect wire connector at horn.
Fig.1 Horn Connector:
2. Using a voltmeter, connect one lead to ground terminal and the other lead to the positive wire terminal.
3. Depress the horn switch, battery voltage should be present.
4. If no voltage, refer to HORNS WILL NOT SOUND. If voltage is OK, go to step Step 5.
5. Using ohmmeter, test ground wire for continuity to ground.
6. If no ground repair as necessary.
7. If wires test OK and horn does not sound, replace horn.
HORNS SOUND CONTINUOUSLY
CAUTION: Continuous sounding of horns may cause relay to fail.
The horn switch (membrane) sometimes can be the cause without the switch being depressed.
1. Remove the horn relay from the intelligent power module.
2. Using a continuity tester, test continuity from the X3 cavity of the horn relay to ground. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
a. If continuity is detected, proceed to step Step 3.
b. If NO continuity replace the horn relay
3. Remove the airbag trim cover from the steering wheel and disengage horn connector.
4. Install horn relay into Integrated Power Module (IPM).
a. If horn does not sound, replace airbag trim cover.
b. If horn sounds, repair grounded X3 circuit from IPM to clockspring in the steering column.
HORNS WILL NOT SOUND
Check horn fuse # 8 in the IPM. If fuse is blown, check for a shorted switch in the airbag module. and refer to FUSE BLOWN section. If fuse is OK, refer to FUSE OK section.
FUSE BLOWN
1. Verify condition of battery terminals and voltage, (Refer to ELECTRICAL/BATTERY SYSTEM - DIAGNOSIS AND TESTING). If battery connections and battery charge is OK proceed to Step 2.
2. Using a voltmeter, test for battery voltage at both sides of horn fuse 7. If voltage is OK, on both sides of fuse, proceed to Fuse OK. If voltage is OK, on one side of fuse, the fuse is blown, proceed to Step 3.
3. Using a suitable ammeter in place of the fuse, test amperage draw of the horn circuit. If amperage draw is greater than 20 amps without the horn switch depressed, a grounded circuit exists between the fuse and the horn relay. Proceed to Step 4. If amperage draw is greater than 20 amps with the horn switch depressed, a grounded circuit exists between the horn relay and the horn. Proceed to step Step 5.
4. Remove the horn relay from the IPM. If the amperage draw drops to 0 amps, the horn switch or circuit is shorted. If the amperage draw does not drop to 0 amps, repair short at the IPM.
5. Disengage a wire connector from one of the horns. If amperage drops and the connected horn sounds, replace the faulty horn. If amperage does not drop with both horns disconnected and the horn switch depressed, proceed to Step 6.
6. Using a continuity tester, with the horns disconnected test continuity of the X2 cavity of the horn relay to ground. If continuity is detected, the circuit is grounded between the Junction Block and the horns. Locate and repair pinched harness.
FUSE OK
1. Remove the horn relay from the intelligent power module.
2. Using a continuity tester, Depress horn switch and test continuity from the X3 cavity of the horn relay to ground.
a. If continuity is detected, proceed to Step 3.
b. If NO continuity, proceed to Step 4.
3. Using a suitable jumper wire, jump across the fuse F62 cavity and the X2 cavity of the horn relay in the Junction Block.
a. If the horn sounds, replace the horn relay
b. If the horn does not sound, proceed to Step 4.
4. Remove airbag trim cover from steering wheel. Refer to ELECTRICAL, RESTRAINTS.
5. Test continuity across horn switch connectors with horn switch depressed.
a. If continuity is detected, repair open circuit between the relay and the horn switch.
b. If NO continuity replace airbag trim cover.
6. Install horn relay into intelligent power module.
7. Disengage wire connectors from horns.
8. Using a voltmeter, with the horn switch depressed test voltage across horn connector terminals of the wire harness.
a. If voltage is detected, replace horns.
b. If NO voltage, proceed to step Step 9.
9. With the horn switch depressed, test for voltage between the X2 circuit and ground.
a. If voltage OK, repair system ground at right cowl area.
b. If NO voltage, repair open X2 circuit between the relay and the horns.