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Comprehension isn't your thing either I see...
1975 ignition control module toasting another one..
- Thread starter pedal2themetal
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SOME people help by explaining without condescending, others feel the need to brag about how smart and rich they are while offering no real help at all.
Which guy do you want to be?
The guy that tries and fails is more respectable than the guy that theorizes but never does anything.
Which guy do you want to be?
The guy that tries and fails is more respectable than the guy that theorizes but never does anything.
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Run from the new ones heres a link about them. A bit long but explains the issues. I usually have some if needed. Also you have the right ballast resistor with it?
1974 Brain Box saves the day.
Was heading out to a local car gathering a couple weeks ago, and a no start on my '76 Truck. Turns out the 1 year old replacement brain box failed. I had a well used 1974 5 pin brain box from my '74 Dart that I had replaced because all the goo on the back had melted out from the hot sun in...
www.forabodiesonly.com
Sixpactogo
Well-Known Member
And piss poor case grounds
Totatly agreed.
I have posted many times, multiple ignition issues are a direct result
of a mismatch between the ECU, distributor, coil, ballast resistor.
The ignition system may work but certain crucial factors are missed
often resulting in a reliability issue and/or component failure.
Just my $0.02...
pedal2themetal
Well-Known Member
HI,Totatly agreed.
I have posted many times, multiple ignition issues are a direct result
of a mismatch between the ECU, distributor, coil, ballast resistor.
The ignition system may work but certain crucial factors are missed
often resulting in a reliability issue and/or component failure.
Just my $0.02...
HHHMMM I did put in a blaster II coil, the rest is stock stuff? So could the Blaster II be causing the problem???Burning up the ICM
Many years back Mopar in their performance manuals posted a recommended list of matching ignition components using the Blaster II coil.
This list specified the ECU, distributor, ballast resistor and Blaster II coil. However note that my experience has been
the earlier OE Mopar ignition components had better reliability than the currently available out-sourced
aftermarket replacement parts. On my 70 RoadRunner I restored 23 years ago still use the same Mopar
ignition components including chrome ECU, electronic distributor, ballast resistor and Blaster II coil. I have had NO
failures..
Just my $0.02...
WileE
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And, we finally get to the REAL nitty-gritty. And the main reasons why some, including myself, never in 50 years had a bad module. Oh... and by the way... I graduated Kindergarten with honors in Coloring.
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Just like with camshaft and lifter failures, some seem to never experience them while others have multiple times.
I think that incompatible related parts are absolutely a possible cause for ECU failures. I have had several fail over the years while never testing the ohm ratings or actual numbers of the coils or ballast resistors I've had. In retrospect, I admit that I should have looked at what was required instead of just using what seemed to work at the time. I have just grabbed a coil, ballast or ECU and put them in place without knowing that each of them had a rating that needed to match the other components.
I think that incompatible related parts are absolutely a possible cause for ECU failures. I have had several fail over the years while never testing the ohm ratings or actual numbers of the coils or ballast resistors I've had. In retrospect, I admit that I should have looked at what was required instead of just using what seemed to work at the time. I have just grabbed a coil, ballast or ECU and put them in place without knowing that each of them had a rating that needed to match the other components.
Less resistance in the resistor puts more stress on the ecu ground switch. And then when guys ditch the resistor all together...
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Halifax Hops posted these charts within this past year.
This one too:
Then this one:
Knowing that the resistor and ECU have to be matched was news to me until I saw it listed. Years ago, I just used junkyard electronic ignition stuff since the engines in the cars I had were stock or barely hotter than stock.
With this car...
When I converted it to electronic ignition for the 440 swap in 2001, I used a Mopar Performance kit but a parts store coil, an Accel, an MP one, an MSD Blaster 2 and over 24 years, I've puked all sorts of ECUs, resistors and coils while never knowing why they failed. If I knew it was entirely my own fault that would be quite humbling but at least I'd learn from it and do it right from then on. That isn't the whole story though as there have been instances where people have had matched components and still have failures. Even Halifax Hops has stated how the newer ECUs don't last like the old ones did. Maybe the best that we can do is buy NOS ECUs and ground them properly.
This one too:
Then this one:
Knowing that the resistor and ECU have to be matched was news to me until I saw it listed. Years ago, I just used junkyard electronic ignition stuff since the engines in the cars I had were stock or barely hotter than stock.
With this car...
When I converted it to electronic ignition for the 440 swap in 2001, I used a Mopar Performance kit but a parts store coil, an Accel, an MP one, an MSD Blaster 2 and over 24 years, I've puked all sorts of ECUs, resistors and coils while never knowing why they failed. If I knew it was entirely my own fault that would be quite humbling but at least I'd learn from it and do it right from then on. That isn't the whole story though as there have been instances where people have had matched components and still have failures. Even Halifax Hops has stated how the newer ECUs don't last like the old ones did. Maybe the best that we can do is buy NOS ECUs and ground them properly.
Geoff 2
Well-Known Member
The Mopar ign coil has a nominal 1.5 ohm pri res. With the 0.5 ohm bal res in series with it, the static current is 6 amps through the ECU, assuming there is no current limiting device inside the ECU.
The Blaster coils have 0.7 ohm pri res. If used with the stock bal res, the ECU current increases to 10 amps.....
The Blaster coils have 0.7 ohm pri res. If used with the stock bal res, the ECU current increases to 10 amps.....
An Accel Super Stock coil would be a closer choice.
I can't comment on the newer produced coils but I have one from 1988.
The OP said it’s on a ‘75 which would have been factory equipped with electronic ignition.
Yup..
Mopar also recommended the Accel Super Coil..
But..
Due to its larger size it couldn't be mounted in the traditional
mounting bracket on the intake manifold..
Just my $0.02...
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See? THIS is helpful. Knowing this, it would explain why an ECU would crap out early… it is getting too much current, leading to eventual early failure.
Keep in mind...
Early Mopar OE electronic ignition systems used a dual element ballast resistor..
(1) resistor for the coil and (1) resistor for the ECU, both designed to limit current..
And later many aftermarket ECUs used a under-designed, cheaper power transistor that could not handle the current..
Just my $0.02...
What makes the car run? Why the points of course.
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