1999 Dodge Neon TEST ENGINE COIL

There are other reasons for this problem besides the coil. How did you come to this conclusion of low voltage. A little more info would be nice but I will do my best to answer this.
#1 check the plugs see if there is any damage to them.
#2 measure the resistance in the spark plug wires.
(you will need to check the manufactures recommended resistance)
#3 unplug the electrical connector from the coil pack and measure the resistance on the primary side of each coil terminal with a digital ohmmeter. Next measure the secondary resistance between the paired high tension towers of each coil.(Once again check the maufacturers recommended resistance.)

This should get you going in the right direction! Hope this helps! MORT