Jump Starting A Dead Battery; Introduction; Jump Starting Precautions - Ford Ranger Maintaince And Repair Manual

JUMP STARTING A DEAD BATTERY

Introduction

Whenever a vehicle is jump started, precautions must be followed in order to prevent the possibility of
personal injury. Remember that batteries contain a small amount of explosive hydrogen gas which is a
by−product of battery charging. Sparks should always be avoided when working around batteries, especially
when attaching jumper cables. To minimize the possibility of accidental sparks, follow the procedure
carefully.
Connect the jumper cables to the batteries and engine in the order shown
NEVER hook the batteries up in a series circuit or the entire electrical system will go up in smoke, including
the starter!
Vehicles equipped with a diesel engine may utilize two 12 volt batteries. If so, the batteries are connected in a
parallel circuit (positive terminal to positive terminal, negative terminal to negative terminal). Hooking the
batteries up in parallel circuit increases battery cranking power without increasing total battery voltage output.
Output remains at 12 volts. On the other hand, hooking two 12 volt batteries up in a series circuit (positive
terminal to negative terminal, positive terminal to negative terminal) increases total battery output to 24 volts
(12 volts plus 12 volts).

Jump Starting Precautions

• Be sure that both batteries are of the same voltage. Vehicles covered by this manual and most vehicles
on the road today utilize a 12 volt charging system.
• Be sure that both batteries are of the same polarity (have the same terminal, in most cases
NEGATIVE grounded).
Be sure that the vehicles are not touching or a short could occur.
•
On serviceable batteries, be sure the vent cap holes are not obstructed.
•
JUMP STARTING A DEAD BATTERY
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CAUTION
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