Table 6-15. Fault Code 05 Or 20 - Wayne Dresser Vista 1 Series Service Manual

Probable Cause
Could be a Wayne Vac error . If dispenser
is equipped with Wayne Vac see correc-
tive action, otherwise, proceed with
probable cause Pulse Jitter.
Pulser jitter.
1. Cracked or broken disc.
2. Defective photocoupler.
3. Dirt blocking opening on pulser disc
4. Dust in housing.
5. Disc tension is not correct.
6. Air in system causing severe hydraulic
shock.
7. Loose plug or wire connection to ISB
assembly.
8. Defective ISB assembly.
9. Defective solenoid drive board.
10. Defective computer.
A. To check the photocoupler, place voltmeter common lead on the pulser select pin of the nozzle position
being serviced. Place the voltmeter positive lead on pin 3 of J9 (J-box side of dispenser) or J10 (opposite
J-box side) on the computer base. Manually rotate pulser drive gear on top of meter assembly of position
being serviced. Voltmeter should fluctuate between 1 and 4 volts. Repeat for pin 6. If blender, also repeat
for pin 5 and pin 9. If any of the readings do not fluctuate, replace the photocoupler. Refer to the appro-
priate drawing in APPENDIX B.
B. Dust blocking one phase of the photocoupler can cause the same symptoms as a defective photocoupler.
If dust is found in the housing do not replace the photocoupler unless the error reoccurs.
February 1997

TABLE 6-15. FAULT CODE 05 OR 20.

B
Corrective Action
Check LED on Wayne Vac Control board. LED should flash
at power up and go OFF. If blinking see Wayne Vac service
manual part number 920023 for corrective action. If OFF
proceed with probable cause Pulse Jitter.
Replace pulser disc.
A
Test photocoupler.
Clean pulser disc.
Clean dust from housing and photocoupler. Adjust disc to
keep it from rubbing on photocoupler. Check for cracks in
housing, replace as necessary.
Check for missing wave washer. Install one if missing.
Repair or replace faulty piping and purge all air from system.
Verify connection to ISB assembly.
Replace complete ISB assembly (board not separately
replaceable).
Replace solenoid drive board.
Replace computer.
Part No. 920160 Rev A
47