5. The battery’s maximum temperature is critical. The electrolyte temperature should never exceed 43°C (110°F) either while operating or charging. Overcharging a battery will cause overheating and warp the battery plates. Maximum battery life will result from maintaining 25°C (77°F) electrolyte temperature. Most of the charging equipment is fully automatic but should be checked periodically to assure proper working order.
2. Randomly measure any component connection or wiring connection with respect to the lift truck chassis for a minimum resistance of 100 000 ohms. Any test point with low resistance must have the short to chassis removed. 3. Always keep batteries clean to minimize current leakage to the chassis. 4. Routinely clean the brush dust from the motors. 5. Be sure that all attachments, such as horns and lights, are designed for no chassis connection (a two wire system).
6. Keep accurate battery records. Regular battery readings should be taken with a battery tester or a voltmeter and a written record kept. Specific gravity and voltage of each cell should be checked and recorded at least once each month. This inspection should be made after an equalizing charge. Readings should never be taken directly after water has been added. Records of all battery maintenance should be made and filed so it will be known which batteries are being abused or wearing out.
Removal Of Shorts To Chassis When a short is found, it must be cleared, even if the machine operates normally. It is necessary to narrow the field of possible problem areas before inspection of individual wires and components. When a low resistance circuit is located, it should be opened at various points. This will permit the shorted wire or component to be pin-pointed for repair or replacement.
Repairs should be made immediately, otherwise the battery may become damaged. Batteries stored in a discharged condition may be difficult to recharge due to sulfate formation.
Control And Power System Operational Checks
Visual Checks 1. Verify that all components and wires are in their proper places. Check fuses, components, contactor tips, wires and connections. Verify that they are not burned, broken or loose.
All operational checks are to begin with the battery connected, directional switch in neutral, drive wheels off the ground and the accelerator and parking brake released. All programmable features should be set to their factory default values before making any adjustments. See the topic Activating Default Settings in the Systems Operations section.
2. Verify that there is no mechanical binding or interference in the contactors. 3. Visually check the parking brake switch, service brake switch, lift switch and accelerator linkage for adjustment or interference problems.
NOTE: Perform all operational checks before returning to the Troubleshooting Check List.
Resistance To Chassis Checks
Check 1: Key Switch, Seat Switch And Power Steering
Resistance between any point in the truck wiring and the chassis should be 100 000 ohms or more.
1. Actuate the key and seat switch. The line contactor should activate and the hydraulic pump motor should turn on. After the time set in programmable feature “6” (Seat Switch Timer), the contactor deactivates and the motor turns off.
Many malfunctions are caused by shorts to chassis. Usually, two shorts must exist before a malfunction will occur. But, since batteries can have chassis leakage, only one short to chassis in the truck wiring can cause problems. To prevent problems because of shorts, do the following:
2. Turn the steering wheel. The pump motor should increase in speed.
1. Disconnect the battery and discharge the HEAD CAP.
MicroCommand Control System
3. After five to ten seconds the line contactor deactivates and the pump motor turns off.
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Testing And Adjusting
