16516-12V Heavy Duty Circuit Tester


Check on 6 and 12V systems. Use on accessories including lights, starters, alternators, cooling and heating components, radios and relays.


  • Ground clip is heavy duty and insulation.
  • The bulb inside the plastic handle will light up if circuit is good.
  • Coil cord flexible design for easy use, wire stretches to 12-feet.
  • Probe is insulated and 90mm / 3.5" long for reaching circuit easily.


VOLTAGE RANGE 6-12V                         
PROBE 90mm / 3.5"
COIL CORD 12-feet
  1. Self-check: connect the alligator clip to the vehicle's negative (-) battery terminal and touch the positive (+) battery terminal with testing probe. If the test light glows, the bulb is working. If not, please replace the bulb.
  2. Turn on the power of the component that is to be checked.
  3. Attach to the ground (usually the vehicle's frame or at the point where the negative battery cable ends) with alligator clip.
  4. Complete the test by touching the component with the probe or by piercing the insulation of the component's wiring.
  5. If the tester light does not glow, then either the circuit is faulty of power or not reaching the circuit.
  6. Repair any wiring insulation damage that is caused by piercing with electrical tape or silicone.