- To test for voltage presence of a low voltage electrical device, such as an irrigation controller, simply attach the alligator clip to one wire and the other wire is touched by the metal probe end by piercing the insulation.
- If the proper voltage is present, the appropriate LED(s) will glow brightly. For example, on 24V irrigation controller, the 6V, 12V and 24V LED's will glow brightly, the 48V LED will glow dimly. This is because most 24V transformers actually put out approximately 26-28V AC. Similarity on a 12V lighting system, only the 6V and 12V LED's will glow.