Powerbuilt Spark Plug Wire Tester – 648429

For easy testing of spark plug wires. Inductive design.Tester lights up when electrical current is detected.

-Fasten alligator clip end of spark plug wire tester to vehicle ground

-Position receptacle end of spark plug wire tester over spark plug wire

-With engine running, observe clear window in spark plug tester

-Light flashing indicates sound wire

-No flashing light indicates unsound wire or spark plug or connection