22 Forward Drive Function Inoperative; 23 Reverse Drive Function Inoperative; 24 Brake Will Not Release; 25 Two Or More Functions At One Time - Skyjack 3215 SJIII Compact Series Service Manual

Section 4 - Troubleshooting Information
Electrical System (Continued)
7. Proportional relay 21ACR defective.
- Check relay, replace if defective.
8. Loose or broken wire #2 from proportional relay 21ACR to base terminal block.
- Check continuity. Replace if defective.
9. Proportional controller S7 out of adjustment.
- Adjust controller. Refer to Section 5, Joystick Adjusting Procedure.

4.1-22 Forward Drive Function Inoperative

1. Loose or broken wire #16 from lift/drive switch S3 to base terminal block.
- Check continuity. Replace if defective.
2. Loose or broken wire #16 from base terminal block to forward drive valve coil 4H-16.
- Check continuity. Replace if defective.
3. Forward drive valve coil 4H-16 defective.
- Check continuity through coil. Replace if defective.
4. Loose or broken wire #02 from forward drive valve coil 4H-16 to base terminal block.
- Check continuity. Replace if defective.
5. Open diode D16.
- Check diode. Replace if defective.

4.1-23 Reverse Drive Function Inoperative

1. Loose or broken wire #15 from lift/drive switch S3 to base terminal block.
- Check continuity. Replace if defective.
2. Loose or broken wire #15 from base terminal block to reverse drive valve coil 4H-15.
- Check continuity. Replace if defective.
3. Reverse drive valve coil 4H-15 defective.
- Check continuity through coil. Replace if defective.
4. Loose or broken wire #02 from reverse drive valve coil 4H-15 to base terminal block.
- Check continuity. Replace if defective.
5. Open diode D15.
- Check diode. Replace if defective.

4.1-24 Brake will not Release

1. Diode D-16 forward or D-15 reverse is shorted or open.
- Check diode. Replace if defective.
2. Loose or broken wire #17 from base terminal strip to brake coil 3H-17.
- Check continuity. Replace if defective.
3. Brake valve coil 3H-17 defective.
- Check continuity through coil. Replace if defective.
4. Loose or broken wire #02 from brake valve coil 3H-17 to base terminal block.
- Check continuity. Replace if defective.

4.1-25 Two or more Functions at one time

1. Shorted diode.
- Check continuity of all diodes. Replace if defective.
SKYJACK, Page 10
Service and Maintenance
SJIII Compact Series
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