F 350 4WD Pickup V8-7.3L DSL (1988)
Cruise Control Module: Testing and Inspection
Use only a multi-meter of 5000 ohm/volt rating or higher when performing amplifier test.
ON CIRCUIT TEST
1.
Turn ignition On.
2.
Connect a voltmeter between light blue wire w/black hash and ground on models except Ranger, Bronco II, Explorer and Aerostar or white wire
w/purple stripe and ground on Ranger, Bronco II, Explorer and Aerostar.
3.
Battery voltage should be indicated when On switch on steering column is depressed and held. If battery voltage is not indicated, check horn relay
and perform CONTROL SWITCH TEST.
4.
Release On button. Voltmeter should indicate 7.8 volts indicating On circuit is engaged. If voltage does not remain, check connector amplifier
ground, fuses or circuit breakers or replace amplifier with known good amplifier and repeat test.
5.
Replace as necessary.
OFF CIRCUIT TEST
1.
Turn ignition On.
2.
Connect a voltmeter between light blue wire w/black hash and ground.
3.
Depress Off button. Voltage should drop to zero indicating On circuit is de-energized.
4.
If voltage does not drop to zero, perform CONTROL SWITCH TEST.
5.
If switches are as indicated, replace amplifier with known good amplifier and repeat test.
SET-ACCELERATE CIRCUIT TEST
1.
Turn ignition On.
2.
Connect a voltmeter between light blue wire w/black hash and ground.
3.
Depress On switch, then hold Set-Accel button on steering wheel. Voltmeter should indicate 4.5 volts. Rotate steering wheel back and forth and
check for voltmeter fluctuations. If reading varies more than .5 volts, perform CONTROL SWITCH TEST.
COAST CIRCUIT TEST
1.
Turn ignition On.
2.
Connect a voltmeter between light blue wire w/black hash and ground.
3.
Depress On switch, then depress and hold Coast button on steering wheel. Voltmeter should indicate 1.5 volts. If all functions are as indicated,
perform servo check and sensor tests, replace amplifier with known good amplifier and repeat test.
RESUME CIRCUIT TEST
1.
Turn ignition On.
2.
Connect a voltmeter between light blue wire w/black hash and ground.
3.
Depress and hold Resume button. Voltmeter should indicate 6.5 volts. If all circuits are functioning properly, perform SERVO ASSEMBLY
TEST using a known good amplifier. Do not replace amplifier before performing servo test.
