Mallory Unilite wire diagram Options

[Geezer914]

Picture 1 is from the module install instructions
[u]
Picture 2 is from the Unilite installation instructions
I fried another module having it wired according to the installation instructions. Picture 2 looks like it bypasses the ballast resistor and sends 12 volts to the distributor, thus frying the module!

[jim_hoyland]

Been there, done that: the module is a weak point in the Mallory. It's been said they either work, or don't work, no between.
Others, including myself, experienced a condition where they temporarily stop working. This is the worst ! The car stops running, you look for the cause, maybe move a wire or two, get back in the car and it starts up. You think you fixed it.

I highly recommend moving on to a1-2-3 Ignition; highly reliable.

[Jack Standz]

Just some more information to consider, if you haven't already:

This damage could have been caused by many things, such as: power surge from an alternator, high resistance spark plugs and plug wires, improper ground wires, if someone has given you a jump, if you have given someone a jump, or battery chargers, which can also damage ignition modules. If voltage always stays below 2 volts and never increases up to 11-12 volts, then the module has been spiked by high voltage and needs to be replaced.

If you use an active power filter, they can be defective (had one that was brand new, but dead which caused lots of time spent trying to figure out why the ignition system wasn't working).

All Unilite distributors need coils with a minimum amount of 1.4 Ohms primary resistance. Coils are 12 volts; however, they do have different amounts of primary resistance, which is measured in Ohms. You can still use a coil with less than 1.4 Ohms, but you must install a Ballast Resistor (Mallory #700) between the coil and the distributor, install on Red wire coming out of the Unilite distributor. It is Important to know that the Unilite distributor will work initially on the engine with less than 1.4 Ohm, BUT NOT FOR LONG. It only takes a short period of time to burn up the module using a coil with the wrong resistance.

When you select a coil for any High power CD ignition box like the Mallory Hyfire CD boxes, the Mallory Hyfire CD boxes MUST always use a coil with LESS than 1 Ohm of primary resistance.

Also, may want to check that the positive and negative terminals on the coil are wired correctly (don't assume it is, because a points based ignition system will work enen if the coil is wired backwards). If backwards, it'll fry the module very quickly.

[Geezer914]

I bought an MSD Blaster II epoxy coil with .7 ohms resistance and a .8ohm ballast resistor. Wired up as in picture 1.