Mercury MotorGuide VariMAX Manual page 24

WIRING AND BATTERY INFORMATION
4. Connect a jumper cable (common ground bond) from the trolling
motor battery "d" negative (–) terminal to the engine battery
negative (–) terminal.
NOTE: Vessels with multiple batteries, must have a common ground
bonding circuit. Not establishing a common ground between the vessel
batteries, may cause severe corrosion, electrolysis, or an electrical
shock.
a
b
a - Power cables to trolling motor
b - 50 amp manual reset circuit breaker
c - Trolling motor battery "c"
d - Trolling motor battery "d"
e - Series cable connection
f - Common ground bond
g - Engine starting battery
h - Power cables to engine
c d
20
g
e
f
h
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