Peterbilt Medium Duty Truck Owner's Manual - Peterbilt Motors

Electrical System
Connect the batteries:
WARNING! When connecting jumper cables,
make sure they can not get caught in any moving
parts in the engine compartment. You could
be killed or 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.
Preventive Maintenance
• Then start the vehicle that has the discharged
(dead) battery.
If the engine fails to start, do not continue to crank the
starter but contact the nearest Authorized Service
Center.
Remove jumper cables:
WARNING! When disconnecting jumper cables,
make sure they do not get caught in any moving
parts in the engine compartment. You could be
killed or seriously injured.
Reverse the above procedure exactly when removing the
jumper cables. With engine running, disconnect jumper
cables from both vehicles in the exact reverse order (Steps 4
– 1), making sure to first remove the negative cable from the
vehicle with the discharged battery.
Battery Charging
Except for using small trickle charges (as explained on Page
226) to maintain battery condition, you should have your
vehicle's batteries charged by a qualified service facility.
– 224 – Y53-6027 Medium Duty (R05/09)