Then You Are In The Right Place!

This Will Tell You How To Use A Low Buck HEI Module Instead!

I drive Jeeps. Lot's of Jeeps.
I have great fun with my Jeeps, and like everyone else, I have to work on my Jeeps.
I don't like doing the same job over and over and over again... That's a drag.
One of the things I detest about Jeeps from '79 to '90 is the amazing regularity with which the IGNITION MODULE QUITS!

Ignition module failure is a pain in the ass at the best of times, and when you are hunting or trail riding several miles from civilization, it's maddening.

Don't get me wrong here, I think the Motorcraft/DuraSpark (yes, from Ford) did a great job when quality control was actually exercised.
I've had factory DuraSpark modules last 20 years and not complain.
Good modules can still be had from MSD and other aftermarket sources, but the 'Discount Store' and 'Auto Jerks' modules suck.
It's the aftermarket modules made in Korea, South Africa, China, Philippines that I'm having trouble with... There is no reason a module should have to be changed 3 or 4 times a year!

So to that end, I'm posting this aftermarket module replacement with instructions.
What I'm doing is using a GM HEI module in place of the aftermarket DuraSpark types.

This is the culprit, a 'Standard Ignition' version of a DuraSpark module.
(not to be confused with the real DuraSpark module...)
Purchased in March of '05 from a local discount auto parts store.

This particular module has been replaced every three months, or 3 times in 9 months.
When it quit this time, I knew there wouldn't be a 4th time...

Going for 6 years now with out any signs of a failure (except when I cake mud on the terminals, Then it needs to dry out before it will run again, so protect your terminals!.

Here are the plans for a direct replacement for the Aftermarket DuraSpark modules.

There are a few things to remember here,
This thing needs a good heat sink to take the heat produced in operation away!
I'm using a large piece of copper plate, you can use aluminum or anything with a rigid, flat, clean surface.

DO NOT Use Dielectric Grease!
The module you buy will probably have a package of colorless dielectric grease with it.

Buy some heat sink compound (also goes by 'Heat Transfer Paste').
Radio Shack p/n 276-1372 A (around $3) works very well.
So will any computer CPU compounds that you may have lying around.

3. The Diode is for the 'Starting' or 'Cranking' circuit.
Some Jeeps are wired with ignition switches that don't require this part.
To test yours, pull off the module 2 wire plug, and test the HARNESS side of the module 'Red' wire.
If it's 'Hot' during cranking, you don't need the diode or to hook the 'White' wire to anything.
The diode I use is Radio Shack p/n 276-1144 or p/n 276-1143.

4. The HEI module I use is from a '79 Chevy Impala with a V-8 engine,
Or any GM HEI 4 Pin Module for a V-8 engine used from about '75 to about '81
The same module was used for every car, 4, 6 or 8 cylinder, and more places have the 'V-8' version in stock...
(I know, they are all the same, but most places, if the computer doesn't list it, the kid can't find one)

What I do is cook the DuraSpark module in the oven for about an hour.
250 to 300F for about an hour seems to loosen up the sealer in the module, and you can pry it out.
If you want to keep in good with the little woman, you may want to use a disposable pan or line your pan with aluminum foil... Just in case yours has the sealer than likes to bleed out...

Save as much of the wiring harness as you can! Get the module apart, and cut the wires off at the circuit board if at all possible.
This is the 'Pig Tail' for the module and the basis for your upgrade...
Wires cleaned, stripped, separated and ready to go...

And this is the Pig Tail with some crimp terminals attached to it.
Notice these terminals have heat shrink wrap built into them? Saves you some time when you don't have to add heat shrink to everything!

This is the typical GM HEI module, and the mount I'm using for this application.
As you can see, I've mounted the condenser very compactly with the module.
A condenser isn't required, but it will sure help take the ignition noise out of your radio!
Notice the Heat Sink Compound. Never mount a module with out it!

There really isn't much to this, and as you can see by the pictures, some #8x32 screws & nuts, some push on crimp connectors and a little imagination is all it takes.

The thing you have to watch the most is Magnetic Pickup polarity.
Follow the diagram for the correct Ford to GM pickup conversion.

The only draw back to this module change I can find is when you are starting the vehicle... Ford/DuraSpark used a starting circuit that retarded the timing about 8 and made it easier to start the vehicle when it was hot.
The HEI has no provision for this 'Starting' circuit. This will make the starter sound like it's 'Dragging' or the battery is low sometimes when you are 'Hot Starting'.

Also, keeping the HEI module out of harms way can be a little tricky sometimes...
Most of us that use the HEI module put our heat sink mount right back in the case from the DuraSpark module.
This is fine if you don't get yours under water. I've had mine under mud, and it WILL short out if submerged.
If you do flood the module location regularly, you may want to move the module to a safer location.
It's easy to do, all you have to do is add more wire when you are attaching to the 'Pig Tail' and move the module where ever you want to.
Remember to keep the Orange and Violet pair twisted the entire length, and try not to bundle them with the power supply wires. (Red & White)

Armor For Your HEI...
I know two guys that used the smaller Army ammo cans for heat sinks, and with the air tight lid, made their modules waterproof and armored at the same time!

HEI & Emissions...
Although this is technically 'Illegal' to do on an emissions controlled vehicle, may people have reported being able to pass emissions testing with the 'Stealth HEI' unit.
(Stealth HEI being described as a HEI module in a DuraSpark case)
When housed in the DuraSpark case, all emissions mandated and regulated components look to be in order, so you pass visual, and the curve ignition curve in the HEI seems to allow people to pass emissions tail pipe testing.
That's just a little tip for you living in the 'Smog Nazi' states...
A friend of mine name John Shrink turned me on to the 'Stealth HEI' in his Smog Nazi controlled vehicle.
He does snow plowing and parking lot/drive salting in the winter, so you can imagine what his wiring harness looks like!
He wears by this module change and accessability to the wiring for the module.