Mercury 80 Owner's Manual page 80

BATTERY CABLE CONNECTIONS
Single Outboard
a - Red sleeve - positive (+)
b - Black sleeve - negative (–)
Dual Outboards
Connect a common ground cable (wire size same as engine battery cables) between negative (–) terminals on
starting batteries.
a - Red sleeve - positive (+)
b - Black sleeve - negative (–)
OUTBOARD INSTALLATION
b
(-)
a
b
(-)
c
a
c
c - Cranking battery
a
b
(-)
d
c - Ground cable
d - Cranking battery
74
(+)
or86
d
or87