MG MG3 Owner's Handbook Manual page 173

EMERGENCY INFORMATION
Remove the ignition key and switch off ALL electrical
equipment of BOTH vehicles, then follow the instructions
below:
1 Connect the RED booster cable between the positive
（ + ） terminals of both batteries.
BLACK booster cable from the negative （ - ）
terminal of the donor battery （A） to a good earth
point (an engine mounting or other unpainted surface,
for example), at least 0.5 m from the battery and well
away from fuel and brake lines on the disabled vehicle
（B）.
IMPORTANT
DO NOT connect a booster cable to the negative
(-) terminal of the discharged battery! This may
result in damage the electrical components.
2 Check that the cables are clear of moving parts of both
engines, then start the engine of the donor vehicle and
allow it to idle for a few minutes.
156
3 Now start the engine of the vehicle with the
discharged battery (DO NOT crank the engine for
more than
4 Once both engines are running normally, allow them
Connect the
to idle for two minutes before switching off the engine
of the donor vehicle and disconnecting the booster
cables. DO NOT switch on any electrical circuits
on the previously disabled vehicle until AFTER the
booster cables have been removed.
5 Disconnecting the booster cables must be an exact
reversal of the procedure used to connect them,
i.e.disconnect the BLACK cable from the earth point
on the disabled vehicle FIRST.
NEVER turn on any electrical equipment on the
started vehicle before removing the booster cables.
10
seconds).
IMPORTANT