270 MAINTENANCE AND LUBRICATION This is a serial communication interface. It conforms to the SAE/ATA J1708 Recommended Practice for Serial Data Communications Between Microcomputer Systems in Heavy-Duty Vehicle Applications. (See the Warning above.) CB Radio Power Jack The CB radio power jacks are located on the dashboard of the day cab, and on the headliner of the sleeper. Power Jack (+) This is a 12-volt, switched battery connection. It is to be used to power the vehicle’s CB radio. It is protected by a 15-amp circuit breaker and will supply power when the key is in the ACCESSORY position or ON position. Power Jack (-) This is a ground connection. It is to be used as a power return connection for the vehicle’s CB radio. Body Builder Connectors The Mack® Granite™ GU axle back chassis offers two optional body builder interface connectors located inside the frame rail on the right-hand side of the chassis behind the cab.
C0029856
Inside the Frame Rail 1. Upper Connector 2. Ground Stud
3. Lower Connector
