18 No Drive Or Steer When Platform Fully Lowered; 19 No Drive Or Steer When Platform Elevated; 20 Elevated Drive Speed Does Not Activate; 21 Work Platform Drives In Slow Speed Only - Skyjack 3215 SJIII Compact Series Service Manual

Service and Maintenance
Electrical System (Continued)

4.1-18 No Drive or Steer when Platform Fully Lowered

1. Loose or broken wire #71 from base terminal block to drive override limit switch LS6.
- Check continuity. Replace if defective.
2. Defective drive override switch LS6.
- Check switch. Replace if defective.
3. Loose or broken wire #19 from drive override limit switch LS6 to base terminal block.
- Check continuity. Replace if defective.

4.1-19 No Drive or Steer when Platform Elevated

1. Pothole protection bars not fully lowered.
- Clear obstructions. Repair as needed.
2. Loose or broken wire #71 from base terminal block to pothole protection limit switch LS4.
- Check continuity. Replace if defective.
3. Defective pothole protection limit switch LS4.
- Check switch. Replace if defective.
4. Loose or broken wire #72 from pothole protection limit switch LS4 to base terminal block.
- Check continuity. Replace if defective.
5. Loose or broken wire #72 from base terminal block to pothole protection limit switch LS5.
- Check continuity. Replace if defective.
6. Defective pothole protection limit switch LS5.
- Check switch. Replace if defective.
7. Loose or broken wire #19 from pothole protection limit switch LS5 to base terminal block.
- Check continuity. Replace if defective.

4.1-20 Elevated Drive Speed Does Not Activate

1. Loose or broken wire #59 from base terminal strip proportional relay 21ACR.
- Check continuity. Replace if defective.
1. Loose or broken wire #59A from proportional relay 21ACR to resistor RST2.
- Check continuity. Replace if defective.
2. Resistor RST2 open.
- Check resistor ohms, it should be 30 ohms. Replace if defective.
3. Loose or broken wire #02 from resistor RST2 to base terminal block.
- Check continuity. Replace if defective.
4. Proportional relay 21ACR defective.
- Check relay, replace if defective.

4.1-21 Work Platform Drives in Slow Speed Only

1. Open diode D17-1.
- Check diode. Replace if defective.
2. Loose or broken wire #17A from base terminal block to high speed limit switch LS1B.
- Check continuity. Replace if defective.
3. Open or defective high speed limit switch LS1B.
- Check switch. Replace if defective.
4. Loose or broken wire #21 from high speed limit switch LS1B to low voltage protection resistor RST3.
- Check continuity. Replace if defective.
5. Defective low voltage protection resistor RST3.
- Check resistor. Replace if defective.
6. Loose or broken wire #21A from low voltage protection resistor RST3 to proportional relay 21ACR.
- Check continuity. Replace if defective.
SJIII Compact Series
143909
Section 4 - Troubleshooting Information
SKYJACK, Page 9