1986+ Mercury 6/8/9.9/10/15HP 2-stroke Factory Service Manual, Page 55Get this manual

OUTBOARD INSTALLATION
Battery Cable Connections
SINGLE OUTBOARD

aRed sleeve (positive)Black sleeve (negative)Starting battery DUAL OUTBOARD

• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives