Skyjack SJ 4632 - 25 Power Extension Platform will Not Extend or Retract; 26 Power Extension Platform will Not Extend; 28 Two or more Functions at One Time

SKYJACK, Page 12 SJIII Conventional Series
143911
Section 4 - Troubleshooting InformationService and Maintenance
Electrical System (Continued)
4.1-25 Power Extension Platform will not Extend or Retract
1. Lift/Drive switch S3 not in lift position.
Move switch to lift position. -
2. Loose or broken wire #09 from lift/drive switch S3 to power extension platform enable switch S12.
Check continuity. Replace if defective. -
3. Power extension platform enable switch S12 defective.
Check switch. Replace if defective. -
4. Loose or broken wire #09A from power extension platform enable switch S12 to platform extend/retract
switch S11.
Check continuity. Replace if defective. -
5. Loose or broken wire #21B from platform control box to base terminal block TB-1.
Check continuity. Replace if defective. -
6. Open diode D21B-1.
Check diode. Replace if defective. -
7. Open diode D21B-2.
Check diode. Replace if defective. -
8. Loose or broken wire #02 from extend valve coil 4H-26 to retract valve coil 4H-27 to platform control
box.
Check continuity. Replace if defective. -
4.1-26 Power Extension Platform will not Extend
1. Powered extension platform extend/retract switch S11 defective.
Check switch. Replace if defective. -
2. Loose or broken wire #26 from power extension platform extend/retract switch S11 to extend valve coil
4H-26.
Check continuity. Replace if defective. -
3. Extend valve coil 4H-26 defective.
Check continuity through coil, replace if defective. -
4. Open diode D26.
Check diode. Replace if defective. -
5. Loose or broken wire #02 from extend valve coil 4H-26 to platform control box.
Check continuity. Replace if defective. -
4.1-27 Power Extension Platform will not Retract
1. Powered Platform extend/retract switch S11 defective.
Check switch. Replace if defective. -
2. Loose or broken wire #27 from power extension platform extend/retract switch S11 to retract valve coil
4H-27.
Check continuity. Replace if defective. -
3. Retract valve coil 4H-27 defective.
Check continuity through coil, replace if defective. -
4. Open diode D27.
Check diode. Replace if defective. -
5. Loose or broken wire #02 from retract valve coil 4H-27 to platform control box.
Check continuity. Replace if defective. -
4.1-28 Two or more Functions at one time
1. Shorted Diode.
Check continuity of all diodes. Replace if defective. -