Cruise Control Test Procedures For GL SW/Sdn/3DR
The required components are:* SOA386C401 Specific Cruise Control Module Tester Box.
* SOA386C405 Specific Cruise Tester Harness for 1987 My vehicle.
NOTE: Turbo vehicles using adapter SOA386C201 do not use a vacuum reservoir. These vehicles may also be diagnosed using the following information. An external vacuum source, such as an A/C evacuation pump, must be used as a vacuum source for these vehicles. This alternate vacuum source is to be hooked directly to the valve body at the "vacuum" port.
CAUTION: DO NOT START WITH THE TESTER INSTALLED.
1) Start car and run engine for at least one minute to build up vacuum. Shut engine off.
2) On Sedan/SW/3 Door models remove driver side under-dash panels. Loosen attaching screws for Electronic Module and remove Module. Re-fasten the screw containing the ground wire firmly to ensure ground on SW/SDN/3 Door models. Disconnect cruise wiring harness from Electronic Module. Attach Module Tester to cruise harness and Electronic Module.
3) Control switch operation may be checked with ignition key and the Cruise Control in the Off position. Operating the control switches in their respective positions, Resume - Coast/Set, should cause the corresponding light on the Module tester to illuminate. If the corresponding lights do not illuminate, check the 15 amp fuse in position #3 of the fuse box, which is the stop light fuse.
4) Turn ignition key to On position. TACH light on tester box should be On. If not, check the yellow wire connection to the negative side of ignition coil.
5. Turn the Cruise Control On by pushing main dash Cruise On/Off switch. The following lights should be On. If these lights do not illuminate, first check 15 amp cruise fuse in position #21 and the power lead to the cruise (green wire/red tracer with blue connectors) to confirm connection.
* Safety
* Neutral - On A/T cars the light will be On in Park or Neutral. Module Tester will not operate for A/T in this position. place the car in Drive and the light will go out.
- On M/T cars the light will go On when the clutch pedal is depressed.
* Tach
* Off
* Ignition
* Speed - May be on or Off depending on speed sensor reed switch contacts. To check, roll the car several feet and light will blink On and Off. If it does not, check the cruise harness conection to the speed sensor, wiring continuity to the speedometer head and the ground wire. If they check good, the sensor in the speedometer may be faulty and should be replaced according to applicable Service Manual instructions.
* Vac, Vent - If any of these lights are Off, check for poor wiring connections at the valve body or at the safety switch. If connections are correct, the valve body should be checked.
6. Depress brake pedal - BRAKE/CLUTCH light will come On. SAFETY, VAC, VENT will go OUT. If not, adjust switch(s) to achieve correct operation and check proper switch and wiring connections.
7. Momentarily press Set button and release - Safety and Vent should go Out. Accelerator pedal should go toward floor. Vent may flicker. The following lights will be On - TACK, OFF, IGNITION, VAC. If the lights respond as indicated but the pedal does not move, the Module is good and the remainder of the system is at fault. Perform Reservoir and Servo test as described in Step 14. If the lights and the pedal do not respond as indicated, the Module may be faulty. Perform further tests as described in Steps 9, 13, 14 and 15 before condemning Module.
8. Depress brake pedal in automatic transmission vehicles and the accelerator pedal should return. When depressing the brake pedal, lights will function as described in Step 6.
Depress the clutch pedal. The following lights should come On - SAFETY, NEUTRAL, VENT
Release the clutch pedal, lights On now - SAFETY, TACK, OFF, IGNITION, VAC, VENT. If not, re-check switch adjustments and switch continuity.
9. The FHI line installed Stop Lamp Switch (OEM) is open with pedal at rest having voltage on one side of the switch at all times. Depressing the brake pedal will close the switch and voltage should be present at both terminals.
The Brake Safety Switch is closed with pedal at rest having voltage present at both sides of the switch. To check switch separately, ground one end of test light and probe at one side of the switch with the white wire w/red tracer. The test light will go out when the brake pedal is depressed. Be sure that the key and cruise are still on.
The Clutch Safety Switch is open with the clutch pedal at rest. To check the switch separately, apply 12 volts to one side of switch and connect a test light to other side and to ground. Test light should illuminate after the clutch pedal is depressed. Release the pedal and the light should go out.
10. Press Resume button and hold. Accelerator pedal will go toward floor and the Safety, Vent lights go out. Vac will flicker. Release Resume button. Lights On now - TACK, OFF, IGNITION, VAC.
11. Now press and hold Coast/Set button. Set and Vent should come On with button function. Lights On - SET, TACH, OFF, IGNITION, VALVE. VENT. Accelerator pedal should return to idle position.
12. Release button when accelerator pedal returns to idle position and pedal may go toward floor again, depending on vacuum supply remaining. Vent light should go Out but may flicker. Lights On - TACK, OFF, IGNITION, VAC.
13. Disconnect tester - Start engine to build vacuum, shut engine off, re-connect the Tester and repeat test as necessary to confirm proper operation. Let the engine run long enough to build an adequate vacuum supply.
14. In the event that the unit does not pass any of the above tests, the three buttons on the Module Tester may be used to isolate valve body, vacuum hose, and servo problems.
a. Repeat Step 12 to build vacuum supply if necessary.
CAUTION: BE SURE ENGINE IS OFF BEFORE CONTINUING.
b. Depress Safety, Vent and Vacuum buttons in that order and hold them down. Accelerator pedal should go to the floor.
c. Release the Vacuum button while holding Safety, and Vent button down and accelerator pedal should remain on floor.
d. Release the Vent button and the accelerator pedal should return.
e. Repeat the test but release the Safety button to return the accelerator pedal.
f. Depressing any one of the buttons should produce a corresponding click from the valves under the hood if the valve is functioning and the unit is wired correctly. if the valve body will not pass the above tests, check wiring continuity and if okay, replace the valve body.
15. The reservoir, servo and apply hose may also be tested with a hand pump to isolate component part problems. Connect the pump to the servo apply hose and pump vacuum. Servo should pull accelerator pedal to the floor and keep it there until vacuum is released. Vacuum reservoir can also be checked by evacuating and seeing if vacuum holds.