S E C T I O N 7
TROUBLESHOOTING
Before starting the troubleshooting, you have to:
A. Put the truck on an even and solid surface.
B. Turn off key switch or disconnect the battery
terminals.
1. Unit will not lift (motor does not
run)
• Faulty wiring from fuse to lift switch in handle
• Faulty lift switch
• Faulty wiring from battery positive terminal to
pump contactor to pump motor
• Burned out brushes in pump motor
• Low hydraulic pressure caused by:
¨ Pressure relief valve needs adjustment
¨ Pump check valve stuck open
¨ Faulty solenoid valve
• Faulty wiring from lift switch to solenoid
• Faulty lift contactor
• Defective control circuit fuse
• Chain or roller bound
• Check oil level
2. Forks will not lower
• Look for binding in chains or rollers
3. No electrical power
Dead Batteries:
¨ Keyswitch on "OFF" position
¨ E-stop button depressed
¨ Loose or dirty battery connections
¨ Blown fuse(s)
• Faulty wiring from fuse to travel control switch
• Faulty control switch
• Faulty wiring from travel control switch direction
contactor
• Faulty contactor
PRESTO OWNER’S MANUAL
Page 15
POWER STAK
