Preventive Maintenance Electrical System
Medium Duty
(R10/06) Y53-6008 – 187 –
before proceeding. If no water is available, remove the caps
and cover the filler openings with a cloth. After jump starting
the vehicle, dispose of the cloth.
WARNING! If you do not cover the filler openings
on the battery, electrolyte could boil out of the
openings and hurt someone or damage the vehi-
cle. Replace caps securely if the battery has the
full level of electrolyte. If the electrolyte is low
and no water is available, cover with a cloth.
Preparing the vehicles:
1. Position the two vehicles together, but do not let them to
touch.
2. Turn OFF all lights, heater, radio, and any other acces-
sory.
3. Set the parking brakes: pull out the Yellow button
located on the dash.
4. Shift the transmission into park position. (See Pages 67
and 34 for transmission shifting and parking brake infor-
mation.)
5. Turn engine OFF (booster vehicle).
6. Disconnect ground cable on booster battery.
Connect the batteries:
WARNING! When connecting jumper cables,
make sure they can not get caught in any mov-
ing parts in the engine compartment. You could
be seriously injured.
1. Attach one end of a jumper cable to the positive terminal
of the discharged (dead) battery. This will have a large
red “+” or “P” on the battery case, post, or clamp.
2. Attach the other end of the same cable to the positive (+)
terminal of the good (booster) battery.
3. Attach the remaining jumper cable FIRST to the negative
terminal (black “–” or “N”) of the good battery.
4. Attach the other end of the negative cable to a bare
metal part bolted to the engine block or clamp directly to
the engine block if possible.
IMPORTANT: Always connect positive (+) to positive (+)
and negative (–) to negative (–).
5. Start the engines:
• Start the vehicle that has the good battery first. Let it
run for a few minutes.
• Then start the vehicle that has the discharged
(dead) battery.
