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How to Troubleshoot the Installation of an Electric Fence

Fence image by Om from

An electric fence only works properly if the fence charger, controlling breaker, ground wire, positive wire, electrified fence wires and insulators are set up correctly. Troubleshoot the installation of an electric fence by looking at each component. Since so many components make up the electric fence, it is easy to miss the cause of an electric fence system failure. Often, the property owner must examine the components more than once.

Make sure the fence charger works. The charger should be located in a shelter or outbuilding, where it is protected from weather. Look for a flashing light on the front of the charger. Listen for the periodic popping sound of the electric spark. If the indicator light is not flashing and there is no sound of a spark, make sure the charger is plugged in and check the breaker box for a thrown breaker.

Look at the connector wires. Follow the ground wire; it should connect to a grounded (probably copper-coated steel) rod. The positive wire should connect to a fence wire. A wire should connect this electrified wire and any fence wires that should be electrified.

If the fence charger is working but the fence does not give off a shock, unplug the charger. Walk the fence perimeter and remove fallen tree branches that could have grounded out the fence. Pull or cut weeds that have grown tall enough to touch the fence wires. All wires should be connected to fence posts with plastic insulators. Look at each insulator; if a wire has slipped off an insulator and is touching a metal post then the fence is grounded out at that point. Put the wire back on the insulator. If the insulator is broken and will not secure the wire, replace the insulator.

If an insulator has fallen off the post, make sure the insulator is the right type for the post. If the fence posts are metal T-posts, the insulator should snap onto the post with an arm and hold the wire with a hook on the opposite end. If the posts are round, the insulators should have a round hole through them with a threaded ring. Tighten the ring.

Plug in the charger. Test the fence with a circuit tester. Hold the ground end to a metal post and touch the positive end to an electric wire. If the fence is working, the bulb will light up in sync with the electrical charges. The light in the tester should be bright enough to be seen in broad daylight. If the fence is working well, a spark will jump to the positive end even when the tester is held a millimeter or so from the hot wire.

Walk the fence line again. Check the fence every 20 feet. If the tester light becomes dim or stops picking up a charge, then the fence is grounded between the charger and the point at which there is no charge. Walk back toward the fence charger and continue testing to find the grounded spot.


Avoid getting shocked by the electric fence. Always unplug the electric fence charger when working on the fence. Tag out the charger with a tag or note to let others know that it is being worked on and they must not plug it back in.

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