Volvo VNL 780 Operator's Manual page 470

460 MAINTENANCE AND LUBRICATION
CB Power Studs
CB Studs are available either in the overhead storage compartment, or on the dash.
The red stud is the positive terminal and the black stud is the ground terminal.
For a proper hook-up, use fork-type connectors on the wires or use "banana" plugs.
CAUTION
If stripped wire ends are used, make sure
there are no wire strands that can bridge
between the studs.
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