J 39200 Digital Multimeter

1. Disconnect both ends of each spark plug wire to be tested.

Ensure that the wire terminals are clean before proceeding.

2. Use the J 39200 on the high scale.
3. Connect an ohmmeter lead to each end of the wire.
4. Gently twist the wire while watching the ohmmeter reading.
5. If the ohmmeter reads above 30,000 ohms, no matter how long the wire is, or fluctuates from infinity to any value, replace the wire.
6. If the resistance of the wire being tested is not within the following ranges, replace the wire:

•	0-380 mm (0-15 in) (long wire) = 3,000-10,000 ohms

•	380-635 mm (15-25 in) (long wire) = 4,000-15,000 ohms

•	635-889 mm (25-35 in) (long wire) = 6,000-20,000 ohms

•	Longer wires should measure between 5,000-10,000 ohms per 300 mm (per ft).