Jump-Starting The Engine - jcb JS300 Service Manual

Jump-Starting the Engine

WARNING In temperatures below freezing, the battery electrolyte may freeze if the battery is discharged
or poorly charged. Do not use a battery if its electrolyte is frozen. To prevent the battery electrolyte from
freezing, keep the battery at full charge.
If you try to charge a frozen battery or jump-start and run the engine, the battery could explode.
Batteries produce a flammable gas, which is explosive. Do not smoke when checking the electrolyte levels.
When jump-starting from another vehicle, make sure that the two vehicles do not touch each other. This
prevents any chance of sparks near the battery.
Switch off all circuits which are not controlled by the ignition key.
Do not connect the booster (slave) supply directly across the starter motor.
Use only sound jump leads with securely attached connectors. Connect one jump lead at a time.
The machine has a negative earth electrical system. Check which battery terminal is positive (+) before
making any connections. Keep metal watch straps and jewellery away from the jump lead connectors and
the battery terminals - an accidental short could cause serious burns and damage equipment. Make sure you
know the voltage of the machine. The booster (slave) supply must not be higher than that of the machine.
Using a higher voltage supply will damage your machine's electrical system. If you do not know the voltage
of your booster (slave) supply, then contact your JCB dealer for advice. Do not attempt to jump-start the
engine until you are sure of the voltage of the booster (slave) supply. The negative (-) terminal on the battery
is connected to frame earth.
1. Lower the excavator bucket and dozer blade to the ground, if they are not already there. They will lower
themselves under their own weight when you operate the controls. Operate the controls carefully to control
the rate of descent.
Refer to: Operation > Operating Levers/Pedals (Page 96).
2. Set all switches in the cab to their off positions.
3. Get access to the battery.
Refer to: Maintenance > Access Apertures (Page 191).
4. Connect the booster cables:
4.1. Connect the positive booster cable to the positive (+) terminal on the machine battery. Connect the
other end of this cable to the positive (+) terminal of the booster supply.
4.2. Connect the negative (-) booster cable to a good frame earth on the machine, away from and below
the battery. A good frame earth is a part of the machine frame, free from paint and dirt. Do not use
a pivot pin for an earth.
4.3. Connect the other end of this cable to the negative (-) terminal on the booster supply.
5. Do the pre-start checks.
6. Start the engine.
132
Figure 171.
9831/1100-2
Operation
Moving a Disabled Machine
132