Ford 2002 Explorer Owner's Manual page 246

Roadside emergencies
3. Connect the negative (-) cable to the negative (-) terminal of the
assisting battery.
4. Make the final connection of the negative (-) cable to the provided
jumpstarting bolt ONLY. Connecting to any other exposed component
may cause an explosion.
Do not use fuel lines, engine rocker covers or the intake manifold as
grounding points.
Do not connect the end of the second cable to the negative (-)
terminal of the battery to be jumped. A spark may cause an
explosion of the gases that surround the battery.
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