How to Check the PTO Wiring on a Riding Mower With a Multimeter

A riding lawn mower uses a electric clutch called a PTO ("Power Take Off") to power the belt drive that rotates the cutting blades.

A PTO that is no longer connected to the battery will not operate and the blades will cease rotating. You can check whether the PTO is receiving electrical energy by using a multimeter. The multimeter can be acquired from a hardware store or hobby shop and does not require any training in order to operate. Hardware tools will be needed -- some of which must be rented or bought as they are not common to most households.

Push the riding lawn mower onto a flat surface, for example, the driveway of your home. Put on the parking break. If the ignition key is in the ignition socket, remove it and place it in a back pocket.

Push the lever on the top of the mower (called the "Deck lever or "Clutch" lever) all the way forward towards the front of the mower.

Insert the tip of a jeweler's screwdriver in the corner hole in the mower belt at the front bottom frame of the mower. Wiggle the tip to loosen the spring pin that is inside the hole. Grip the top of the spring pin with a needle-nose pliers. Pull the spring pin out of the hole. Pull the bar out of the hole in the frame. Pull the mower belt that is at the front of the mower off the PTO clutch and place it down on the ground.

Place a jack beneath the front end of the mower. Work the jack to raise the mower. Place a jack stand under each side of the mower, in front of the wheels. Lower the jack so that the mower is now seated on the jack stands.

Remove the connector cap that is on one side of the PTO clutch with your fingers. Place the connector in your back pocket for safety.

Rotate the ohm scale knob on the multimeter to "1X." Place the end of the positive (black) lead attached to the meter against the positive (black) labeled contact exposed now that the connector cap has been removed.

Place the end of the other lead attached to the meter against the bare metal frame of the mower. Read the measurement on the scale. If the measurement does not read 3.7 ohms, or does not register at all, there is a short in the wiring and the mower must be professionally serviced.

Remove the multimeter's leads from the mower. Place the connector cap back on. Place the mower belt back on the front of the PTO clutch. Place the bar back in the hole in the frame. Reinsert the spring pin. Jack up the mower. Remove the jack stands. Lower the mower to the ground and remove the jack. Pull the lever at the top of the mower a notch or two toward you.

Things You Will Need

  • Jeweler's screwdriver
  • Needle-nose pliers
  • jack
  • 2 jack stands

Warning

  • Keep children and pets away from the riding lawn mower when you are working on it.

About the Author

Marshal M. Rosenthal is a technology maven with more than 15 years of editorial experience. A graduate of Brooks Institute of Photography with a Bachelor of Arts in photographic arts, his editorial work has appeared both domestically as well as internationally in publications such as "Home Theater," "Electronic House," "eGear," "Computer and Video Games" and "Digitrends."