Cruise Control: Testing: Amplifier
CAUTION:
DO NOT use a test light to perform amplifier tests as excessive current draw will damage electronic components. Use only a voltmeter of 5000 ohm/volt rating or higher.
- Turn ignition "ON" and connect a voltmeter to blue lead at amplifier 6-way connector. Voltmeter should read 12 volts when the "ON" switch in steering wheel is depressed and held. If no voltage is available, check horn relay circuit and perform CONTROL SWITCH TEST . Release the "ON" button; 12 volts should remain at blue wire indicating the "ON" circuit is engaged. If voltage does not remain, check for ground at amplifier, fuse and/or circuit breaker. Insert a known good amplifier and recheck "ON" circuit if necessary.
- With ignition "ON" and voltmeter connected to blue wire as in step 1), depress the "OFF" switch on steering wheel. Voltage on blue wire should drop to zero indicating "ON" circuit is de-energized. If voltage does not drop to zero, perform CONTROL SWITCH TEST . If switches test good, install a known good amplifier and retest.
- With ignition "ON", and voltmeter connected to blue wire as in step 1), depress the "ON" switch, then hold "SET-ACCEL" button on steering wheel. Voltmeter should indicate approximately 10 volts. Rotate steering wheel and watch voltmeter for variation. If voltage varies more than 0.5 volt, perform CONTROL SWITCH TEST .
- With ignition "ON", and voltmeter connected to blue wire as in step 1), depress the "ON" switch, hold "COAST" button down on steering wheel. Voltmeter should indicate about 6 volts. If all functions check good, perform Servo Test, and Sensor Tests, and insert a known good amplifier and recheck.CAUTION: Do not substitute a new amplifier until actuator coils have been tested. See SERVO ASSEMBLY TESTS .