Control Switch

1. Push the horn button. If the horn doesn't blow, the horn circuit is defective. If the horn blows, connect the positive probe of the voltmeter to terminal 6 (Lt. Green/Red) and negative probe to terminal 9 (Black) at control unit connector. Push the "SET" switch. See Figure .
2. If there is 12 volts, go to step 4). If there is no voltage, connect the voltmeter positive probe to terminal 37 (Lt. Green/Red) of slip ring connector. Connect negative probe to ground. Push the "SET" switch and read voltage with slip ring connector connected.
3. If there is 12 volts, there is an open in wiring harness. If there is no voltage, remove the steering wheel and check control switch as outlined in this article. If switch tests okay, control ring is defective.
4. If in step 1) there was 12 volts, connect the voltmeter positive probe to terminal 11 (Lt. Green/Black) and the negative probe to terminal 9 (Black) of control unit connector. Push "RESUME" switch. If there is 12 volts, go to step 6).
5. If in step 4) there was no voltage, connect positive probe to terminal 38 (Lt. Green/Black) of control unit connector and negative probe to ground. Push the "RESUME" switch. If voltmeter reads 12 volts, there is an open in wiring harness. If there is no voltage, remove steering wheel and check "RESUME" switch as described in this article. If okay, slip ring is defective.
6. If in step 4) there was 12 volts, check for continuity across terminals 11 (Lt. Green/Black) and 6 (Lt. Green/Red) at control unit connector. If there is no continuity, test is okay. If there is continuity, disconnect slip ring connector and check for continuity between terminal B (Lt. Green/Red) and terminal C (Lt. Green/Black).
7. If there is no continuity, there is a shorted wire in harness from the slip ring connector to the control unit. If there is continuity, check for continuity between terminal B (Lt. Green/Black) and terminal C (Lt. Green/Red) of "SET"/"RESUME" switch connector. If there is continuity, "SET"/"RESUME" switch is defective. If there is no continuity, slip ring is defective.

Fig 1: Control Switch Terminals and Continuity Set/Resume control switch terminal viewed.

Check control switch continuity. There should be continuity between terminals A and C when "SET" switch is in the on position, and continuity between terminals A and B with "RESUME" switch in on position. See Figure .