Reply to "Installing Ford DuraSpark Module - Glenn C"

Ron, I think that list was written by me, I copied it from a Chilton manual. I'll give you guys the real "meat".

Ford 1970's ignition modules 101:

Breakerless ignition showed up in North American Ford vehicles in 1974. The first ignitions were not called DuraSpark, they were referred to as breakerless ignitions. The modules had a green wire strain relief with two harnesses, one connecter with 3 pins, and one with 4 pins. These modules "could" vary as to which wires were grouped in which harness, so you had to be mindful when working on these cars, to make sure the person behind the parts counter gave you the right replacement.

In 1977 Ford began referring to the breakerless ignitions as DuraSpark ignitions, and released two modules simultaneously; the DuraSpark I for California, and the DuraSpark II for the rest of North America. The DuraSpark I module was capable of producing a stronger and more consistent spark under varying engine load conditions which Ford found necessary to meet California emissions standards in 1977. Both DuraSpark modules featured spark retard when starting the motor. I am uncertain if that feature was incorporated into the earlier module. Both DuraSpark modules had two harnesses, one with a two pin connector, and one with a 4 pin connector, 6 wires in total. The earlier module with the green strain relief had 7 wires, it had a blue wire that was not carried over into the DuraSpark modules.

The DuraSpark I module had a red wiring strain relief. It was a very sophisticated ignition module, sensing & controlling the currrent in the coil primary as a means of controlling the current and spark quality produced in the coil secondary. It was only installed in California cars, therefore many hot rodders were not and are still not aware of its existence, or the difference between it and the DuraSpark II module. In 1978 Ford found it could meet California emissions regulations with the less expensive DuraSpark II module in all of its motors except the 302 V8. So California cars with the 302 V8 received the DuraSpark I ignition, and California cars equipped with all other motors got the DuraSpark II ignition like the rest of North America. The same applies to 1979 California cars. 1979 I believe was the last year DuraSpark I was installed in any Ford car. Worthy of mention is the safety feature built into the DuraSpark I module; if the distributor rotor is not turning, the module shuts off current to the coil primary, the ignition cannot fire, so it is safe to work on the ignition without fear of being shocked. NOT SO with any other Ford module. Disconnecting the wrong wire on any other Ford module while you are working under the hood can result in triggering the ignition and shocking you with enough current to stop your heart.

The DuraSpark II module introduced in 1977 has a blue wiring strain relief. It is not much different from the early module with green wiring strain relief. Its reliable and provides a nice spark, but it is less sophisticated than the DuraSpark I. Current in the coil primary is controlled just like it was with a breaker point ignition, with a ballast resistance in line with power to the coil. To provide a hotter spark while starting the motor, there is a second wire supplying the coil that bypasses the ballast resistor to provide full battery voltage when the ignition key is in the start position. This module is the most common module for retro-fitting breakerless ignition to early cars, simply because many people are not aware of the existence of the DuraSpark I module, or they are not aware of the differences. Its also worth mentioning this module can kill you while you are working on the motor unless precautions are taken to avoid an accidental discharge of the ignition!

After 1977 Ford developed other ignition modules with white, brown or yellow wiring strain reliefs that have other features that are unneeded or even undesireable for retro-fitting breakerless ignition. I found in my experience with them that all of the other modules had 3 wiring harnesses. They are designed to work with input from sensors, such as knock sensors, altitude sensors, MAP sensors, etc, and they are designed to control spark timing based on those inputs, to compensate for knock, altitude, engine load, etc. Or they are designed to work in conjunction with Ford's early "EEC" engine management systems. Some of these modules were called DuraSpark II, others DuraSpark III, and beginning in 1981 there was also the "universal" module.

Installation Notes:

1. When purchasing a module for your car, buy it from Ford! The Ford manufactured modules are very reliable. Reliability of the aftermarket modules is hit or miss.

2. DuraSpark modules use a high voltage coil made specifically for DuraSpark ignition. Use the Ford DuraSpark coil or DuraSpark specific replacement. Do not use a breaker point ignition coil.

3. DurSpark coils are oil filled and must be mounted oriented vertically, with the top higher than the bottom. They must not be mounted laying horizontally.

4. Painless Wiring sells a wiring harness for DuraSpark II conversions. It should be applicable for DuraSpak I conversions too, as there is very little difference in the wiring between the two ignitions. It is available at Summit Racing under part number PRF-30812, or JEGS under part number 764-30812.

5. DuraSpark distributors for the 351C will be sourced from a 1977 through 1982 Ford vehicle equipped with a 351M, 400 or 460 cubic inch V8.

6. A ballast resistor suitable for DuraSpark II installations is available from NAPA Auto Parts, NAPA part number ICR23 (1.2 ohms).


cowboy from hell