Product Manual
20 Mighty Mule MM360 Installation Instructions 
Step 2
Place the 12 Volt automotive or marine type battery and 
its weatherproof case within 6 feet of the fence post 
where the opener arm is mounted.
Step 3
Attach the 10 foot battery harness wires provided to the 
terminals of the battery. 
CAUTION: Take care to attach the BLACK wire to the 
NEGATIVE terminal and the RED wire to the POSITIVE 
terminal. Reverse connection will cause damage to the 
control board.
Step 1
With the opener mounted in the upside down 
position remove the Control Board Access Panel 
on the bottom of the opener arm.
ON/OFF 
ON/OFF
Control Board Access Cover
Control Board
Battery Harness 
Connector
Receiver Wires
ON/OFF Switch
Step 4
IMPORTANT: Make sure the power switch on the 
opener arm is in the OFF position.
Run the plug end of the Wire Harness wire up to 
the opener arm and plug it into the battery harness 
connector coming from the control board.
ON/OFF
ON/OFF
Battery Harness Connector
10 foot Harness 
From Battery
0
2
RED to POSITIVE
BLACK to NEGATIVE
Battery Harness
Connector
10 Foot 
Power Cable
CONNECTING THE BATTERY










