The main problem with an electric fence is that the wires can be broken by such unexpected events as a falling tree limb, and animal being spooked into the wire, or an ongoing short causing the wire to burn in two. Fixing a break is a simple process, and only requires 2 pairs of pliers to accomplish.
Step 1: Kill the Power
Before you do anything with your electric fence, kill the power. Unplug the unit completely, and if other may notice the box is unplugged, take a moment to remove the fuses. An electric fence will not cause you any serious harm if it shocks you, but the sudden zap is quite unpleasant.
Step 2: Find the Break
Trace the electric fence wire and find the location of the break. Clear any debris from the fence line which may have contributed to the break. Locate both sides of the break, and pull them towards each other. Stick the ends in the soil to hold them until you are ready to make the splice.
Step 3: The Splice Loop
Choose one end of the electric fencing, and fold it into a small loop, twisting the end of the wire around on itself to form a noose-like loop. Hold the two ends of wire toward each other. If the ends do overlap, you need to make an identical loop on the other end, and attach one end of a short piece of fence wire to it, wrapping it tightly on the old fencing.
Step 4: Making the Splice
Take the remaining free end of wire, and run it through the unused splicing loop. Hold it firmly in the grip of the pliers, and pull the fence through the loop until it is tight. Twist the first inch of excess wire around the straight wire, and clip off any remaining excess. Make sure that both (or all 3 if you had to add a length of wire) loops are tightly wound on the fencing, and that the wire is stretched taut. A poor connection in a splice will result in a non-functional electric fence.
Step 5: Restore the Power
Put the fuse back in, plug the charger up, and turn it on. If there was only one break, the charger should flash to indicate that the fence is now hot. If the charger still indicates a short, you will need to further investigate the fencing.
Step 6: Instant Fence Tester
If you don't have a fence tester, you can make one from a small section of a Christmas light string. Attach a piece of electric fencing to one leg of the light, and bare 1 inch of wire on the other leg. To use the tester, press the long leg into the soil, and hang the stripped back leg over the fence wire to be checked. If the light blinks on and off in time with the charger, you have power at that location.