I am converting my 70 Duster's original ignition system to an electronic.

I have the Distributer / Ballast Resistor / Wiring Harnes, but I lack the ECU atm. Using the single ballast resistor instead of the duel it is recommended that you use the 4-Pin ECU, but is it "Required"?

I have a 5-Pin ECU from another project atm but I read that using it in the above configuration would keep the system from operating. Is this true? Do I need to find a 4-Pin ECU?

Thanks for your time and help.

Jeremy Weimer

5-pin requires the dual ballast resistor. If you install the dual, you can run either the 4-pin or the 5-pin which is handy in "emergency" situations...

D/W

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If it ain't broke, fix it!

Not true. I used a 5-pin, dual ballast resister system on my Satellite. Just clip the green w/red tracer wire and wire it up as you would a 4 pin (four wire) unit. You can use the existing ballast resister: but the ballast that comes in the factory conversion kit has a different value than points resisters.

I went by AutoZone today to see what my options where. Found two items. A Wells CR100 and CR109. CR100 is the 5-Pin ECU and the CR109 is the 4-Pin ECU. 4-Pin was even 3 dollars cheaper so that's the one I picked up

Sounds like I may need to make a run to investigate a new ballast now. Thanks for the info Eric and Dennis.

Hmmmm. All my sources including the DC (mopar Performance) engine book say that the 5-pin must be wired for the dual ballast. Have I ever actually tried running a 5-pin ECU on a car wired for a single ballast, as you report to have? I thought long and hard about it, and the answer is "no". Everything that I have is wired for a dual ballast at the moment (but running 4-pin ECU's), so I have no way to check this, so will have to take your word for it if I understand you correctly. I think we can definitely agree that you can plug a 4-pin ECU into either a single or a dual ballast system and it will work fine, the second resistor is simply not used in that case. A stock dual resistor is 5ohm/.5ohm, by the way

D/W

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If it ain't broke, fix it!

Didn't mean to sound like a smarty-pants Dennis. Reed gave me a complete set up out of an F body (I think) that had all the wires from the box to the distributer, including the wires to the voltage regulator and the dual ballast. All I did was clip the green w/red tracer wire, and wired the blue wire into the run side of the ballast that was in the car (since changed to a .5 ohm) and the other wires to the distributer and coil. Honestly, I have had no problems with it, and I installed it four years ago. A friend did the same with his '71 Fury w/440 and also has had no problems. Oh yeah, change the coil to one made for an electronic ignition. Chrysler changed the coil when they did the change over.

But you used the 5-pin ECU and left the fifth pin (which plugs into the green/red tracer wire) open? I realize you can use the wiring scavenged from a donor car. Matter of fact I've never used the kit.

D/W

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If it ain't broke, fix it!

After Doc looked over my EI conversion article, I realize that I assumed only the 4 wire configuration since it was the simple and direct approach. I was aware that a 5 wire system existed, but I didn't understand or explain or even mention it in the article.

The piece is getting rather long already, but I'm sure the info you've discussed should be included for the sake of sanity and clearity.

Thanks very much for the explaination, and I'm highjacking this thread by asking for input on the article again. Please note that the 5 wire information has not yet been included.

http://www.slantsix.org/articles/leanbu ... rticle.htm

please email me or Doug Dutra if you have any suggestions/ corrections.

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1980 Aspen 225 super six