How to Test an Electric Clutch on a Snow Plow

Testing the Engaging System

1). Place the plow on a lift or raise it with a jack high enough so that you can work underneath it. Secure it in place with jack stands or safety supports.
2). Remove the safety covers underneath the plow to expose the electric clutch system. These can easily be removed by pulling them away from the body of the plow. Once they're removed, you should be able to see the clutch system that operates the plowing mechanism.
3). Turn on the snow plow and allow it to run for several minutes. Have a partner engage the snow plow clutch switch while you visually inspect the undercarriage of the vehicle. With the clutch engaged, the plowing mechanism should lower. When the clutch is disengaged, the plowing mechanism should move up so the vehicle can drive without plowing. If there is no movement in the undercarriage, there is probably a connectivity issue.
4). Turn the snow plow off. Locate the clutch's wiring connector on the top of the frame near the base of the engine. Unplug the wiring connector from the clutch by pulling apart the connectors and the wires. As the wiring connector comes off, the clutch should disengage. If it does not disengage, there is an issue with power to the electric clutch.
5). Test the voltage output of the electric clutch with a voltmeter. There are two wires attached to the wire connector. Test the wire that is not the ground wire with the voltmeter. The ground wire will have a zero voltage output. If the other wire is putting out little or no voltage, there is a power issue with the electric clutch.

Testing the Engaging Switch

1). Turn the plow off and pull the engaging switch back to disengage the plow mechanism. Most snow plows will only turn on when the plow mechanism is disengaged.
2). Start the motor of the snow plow while keeping the clutch mechanism disengaged. With the motor on, engage the clutch so that it lowers the plowing mechanism. Repeat this process several times. If the switch does not lower the mechanism or the switch sticks, there is a problem with the electric clutch's switch.
3). Turn off the snow plow's motor. Visually inspect the area around the clutch for signs of rust, decay or damage. Rust and loose debris in the switch shaft can cause problems with the electric clutch.