Another option that you can use is the back of the hand test. Make sure you're wearing rubber soled shoes and just touch the fence with the back of your hand. It should give you a small little buzz, but nothing major. (Unless your fence charger is malfunctioning.) The above post is correct in testing procedures, with the exception of when using a multimeter you'll probably need to select DC voltage for the test. The way the fence charger works is that the positive terminal goes out to your poly tape, while the negative terminal goes to the ground via 1, 2 or 3 ground rods. When something (such as a horse) touches the wire and the ground at the same time, it completes the circuit, providing a small jolt.