MAINTENANCE AND LUBRICATION 293 Electrical Accessory Connection Points
CAUTION The electrical systems on all MACK chassis include a circuit breaker located in the ground circuit. Any additional electrical components that may be added MUST not be connected directly to the battery or negative connection of the starter. Doing so may defeat the protection provided by this circuit breaker. Components may be ground connected to other locations, such as frame or engine grounding points.
This MACK chassis is ready for convenient installation of electrical accessories. Use only the designated CB jacks on the dashboard, or battery post (12 volts), ignition, ground post, buffered tachometer (RPM) output, and buffered speedometer (MPH) output connections available on the electrical equipment panel. Each connection point is described below. Battery Post (BATT) This is a 12-volt, unswitched battery power connection. It can be used to power external devices that require power at all times, even when the key is turned off. This source is protected by a 20-amp circuit breaker. Ignition Post (IGN) This is a 12-volt, switched battery power connection. It can be used to power external devices that require power only when the key is turned on. This source is protected by a 15-amp circuit breaker. Ground Post (GND) This is a ground connection. It can be used as a power return connection for external devices.
WARNING The tachometer output, speedometer output, and serial links A and B are for specific hookups. These terminals should be used only for their specified purposes and connection to these terminals should be done only by a qualified service technician.
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