Speed Control Operation Is Intermittent

1. Check when intermittent operation occurs. If intermittent operation occurs when vehicle is at cruising speed, proceed to step 2. If intermittent operation occurs when operating control buttons or turning steering wheel, proceed to step 4.
2. Check that there is at least 2.5 inches Hg of vacuum supplied to servo. If satisfactory, proceed to step 3. If not satisfactory, service vacuum supply as needed.
3. Perform servo (throttle actuator) assembly test. If test result is satisfactory, substitute amplifier with a known good amplifier and proceed to step 5. If not satisfactory, replace servo assembly.
4. Perform control switch and circuit test. If test results are satisfactory, substitute amplifier with known good amplifier and proceed to step 5. If test results are not satisfactory, repair circuits or replace horn pad assembly as necessary. When replacing horn pad assembly, clean or service copper brushes and steering wheel ring.
5. If system operation is satisfactory, replace amplifier.