Pinpoint Test 1

Visual Inspection Chart

Flow Chart No. 1 - Symptom - Horn does not operate.
Step 1
Relay check.




1. Place finger on horn relay while helper presses horn button.




2. Does relay click?

Step 2
Battery feed to relay contact set.
1. Remove relay.




2. Check for voltage at relay contact set feed terminal (Y/LB). Voltage should equal battery voltage.




3. Is voltage available?

Step 3
Isolate relay.




1. Connect jumper from relay battery feed terminal (Y/LB) to horn feed terminal (DL) at engine compartment fuse box.




2. Does horn operate?

Step 4




Relay-to-horn circuit continuity check.
1. Install relay.
2. Disconnect feed wire at horn.
3. Check for voltage at horn feed wire while helper presses horn switch.




4. Is battery voltage available?

Step 5
Horn ground circuit check.
1. Check for continuity between horn mounting bolt and clean chassis ground.




2. Is there continuity?

Step 6
Battery feed-to-relay coil.
1. Remove relay.




2. Check for voltage at relay coil feed terminal (Y/B) at engine compartment fuse box. Voltage reading should equal battery voltage.




3. Is voltage available?

Step 7
Relay coil continuity check.




1. Check for continuity across relay coil terminals 1 and 2.




2. Is continuity approximately 0.85 ohms?

Step 8
Relay to steering column circuit check.
1. Install relay.
2. Disconnect 6-pin connector at base of steering column.




3. Check for battery voltage at Y/LG wire of connector.




4. Is battery voltage available?

Step 9
Steering column harness/air bag sliding contact check.




1. Connect 6-pin wiring connector at base of steering column.
2. Remove air bag module.

NOTE
^ Be sure to follow air bag removal safety precautions.

3. Disconnect 5-pin connector from air bag module sliding contact.
4. Check for voltage at sliding contact Y/LG wire.




5. Is battery voltage available?

Step 10
Sliding contact-to-horn switch check.
1. Connect 5-pin connector at sliding contact.




2. Check for voltage at each horn switch upper terminal.




3. Is battery voltage available?

Step 11
Horn switch ground circuit check.

CAUTION
^ Ignition switch should be off. Remove the horn relay.




1. Check for continuity between horn switch lower contact plate and steering wheel armature.




2. Is there continuity?

Step 12
Horn switch continuity.

CAUTION
^ Ignition switch should be off. Remove the horn relay during this test.

1. Depress horn switch at each of the four corners, one at a time.
2. Check for continuity between upper and lower horn switch plate with switch depressed.




3. Is there continuity?

Step 13
Cruise control wire harness continuity.
1. Remove terminals at each upper horn switch.
2. Check for voltage at each terminal.




3. Is there battery voltage?

Step 14
Isolate cruise control switches.
1. Disconnect wiring at cruise control switches.
2. Check for continuity across cruise control switch terminals 5 and 7 on the left-hand side and terminals 1-3 on the right-hand.




3. Is there continuity?