How to Test for a Parasitic Draw on a Four Wheeler

The battery of an ATV is small, relative to a car battery. With small size comes low capacity in terms of how long it can sustain a discharge before becoming depleted. Nevertheless, the charge in the battery should last at least a month. If you have to charge the battery in your four-wheeler every time you ride it, either the battery is bad or something on the four-wheeler is consuming power when the ignition is off. A parasitic draw test will help you locate the problem.

Things You'll Need

  • Battery charger
  • Screwdriver
  • Multimeter with ammeter function
  • Service manual
Show More

Instructions

    • 1

      Remove the seat of the ATV and disconnect the positive battery cable. Connect the charger to the battery and fully charge it.

    • 2
      A multimeter is an essential tool for troubleshooting parasitic loads.

      Disconnect the charger leads from the battery. Set the multimeter to the "Amperes" function. The meter should be capable of measuring at least 10 amperes.

    • 3

      Connect the red meter lead to the battery, and the black lead to the positive battery terminal. The negative battery terminal should still be connected to the battery.

    • 4

      Look at the meter. It should indicate zero amperes, or if the ATV has a built-in electronic clock or trip computer, no more than 0.01 amperes. If it indicates more current than that, make sure the ignition switch is off and disconnect and reconnect the wire connections until you find one that stops the current flow. Use the manual to help you find all of the connections.

    • 5

      Follow the wire from the connection to find the faulty component. The wires are color-coded for easier identification.