Battery System - Description

DESCRIPTION

The battery system for this vehicle covers the following related components, which are covered in further detail:

- Starter Battery (also referred to as the main vehicle battery) - The starter battery provides a reliable means of storing a renewable source of electrical energy within the vehicle.
- Auxiliary Battery - The auxiliary battery is designed to provide small amounts of current over a long time period to power optional equipment such as trailers, lift gates, refrigeration units, and service and emergency vehicles.
- Battery Cables - The battery cables connect the battery terminal posts to the vehicle electrical system.
- Battery Holddown - The battery holddown hardware secures the starter battery in the battery well in front of the driver seat and the auxiliary battery in the battery tray in the engine compartment.
- Auxiliary Battery Tray - The auxiliary battery tray provides a secure mounting location in the vehicle for the battery and an anchor point for the battery holddown hardware.

STARTER BATTERY

The starter battery (also referred to as the main vehicle battery) is located in a floor well forward of the driver seat. A metal cover retained by four screws protects the top of the battery. To access the battery and battery cover the left floor covering must be removed. A breather line runs from the battery through the bottom of the recess well to the outside of the vehicle.

The battery negative cable is routed out of the well to a isolating connector on the left side of the instrument panel center stack, above the accelerator pedal. When vehicle service requires disconnecting the battery this connector provides a convenient method of isolation.

A 300 amp melting fuse is incorporated into the battery positive cable. If the fuse melts, the battery positive cable must be replaced. The main reason this fuse would melt is from reversing polarity while jump starting the vehicle.

NOTE: Removing this isolating connector only disconnects power to the starter battery. If the vehicle is equipped with an auxiliary battery, that must also be disconnected prior to vehicle service.

When optional equipment is installed, the standard 12-volt 100Amp battery may be replaced with a 12-volt 95Amp Absorbent Glass Mat (AGM) battery. Electrolyte levels for AGM batteries should be checked every 25,000 miles or every two years.

AUXILIARY BATTERY

WARNING: The auxiliary battery should only be charged and tested with the OTC One Step Battery Analyzer and Charger or equivalent. Never test the auxiliary battery with a Midtronics Micro 420 battery tester.

WARNING: Never jump start the vehicle with the auxiliary battery. Vehicle jump starting should only be performed at the remote battery terminals in the engine compartment or at the starter battery itself.

The auxiliary battery is located in the left side of the engine compartment. The battery is designed to provide small amounts of current over a long time period, and is not designed for high currents. The auxiliary battery is used to power optional equipment such as trailers, lift gates, refrigeration units, and service and emergency vehicles.

A auxiliary battery cutoff relay is used to prevent discharging the starting battery while operating optional equipment. The relay is located in the driver seat riser. The relay coil is grounded to the vehicle chassis on one side and receives power from the Body Control Module (BCM) on the other. The battery terminal of the relay is connected to fuse four in the fuse/relay block #1. When the engine is running the BCM powers the coil and energizes the auxiliary battery relay. This connects the auxiliary battery to the vehicle battery.

Refer to the Lubrication and Maintenance for the recommended battery maintenance schedules and for the proper battery jump starting procedure. While battery charging can be considered a maintenance procedure, the battery charging procedure and related information are located later of the service manual. The battery must be fully-charged before any battery system diagnosis or testing procedures can be performed.