1994 Miata Coil Pack Bench Test

This is one half of a 1994 coil pack, removed from
its mounting bracket
.

 

These are the electrical connections for the coil pack.
Pin 1: Input that makes the coil spark.
Pin 2: Ground
Pin 3: Output - goes to your tachometer and also to the computer
Pin 4: Twelve volt power.







 

How to bench test.
1) Connect two spark plugs using your ignition wires. The spark plug bodies must touch each other to complete the spark circuit. If not, the coil can be ruined.
2) Add +12 across the power and ground pins.
3) Apply a trigger voltage between the trigger pin and ground. A flashlight battery is enough to do this.. Touching 1.5 volts and removing it will fire the coil..
4) You can see the spark.jump across the two spark plug tips.

   
This is what one technique looks like.

This does not test the tachometer output, which is too fast to see with your eye.

Disclaimer: Not a certifed auto mechanic. Not a Mazda technician. You have 20 thousand volts sparking here, so be careful and do not shock yourself or you could be injured.

The information on this page is my own interpretation and may be flat-ass wrong. Use at your own discretion.