Technical Mopar Electronic Ignition problems

My '60 Plym has a 331 with the elec ignition/LA dizzy. Have been driving it for a few yrs. The other day it wouldn't start. Timing light showed no ignition. Took the ignition module to the store, they tested it & said it was bad. Installed new one & still wouldn't start. Timing light showed a flash when key was turned on to "start" & again when released. Low battery, so I charged it up & it cranked right up. 2 days later I'm back to square one. Guy @ the parts house today didn't know how to test the module so he just replaced the one, but I don't know for sure if the module was bad , it may start, but for how long? The ballast resistor checked good the other day. Could there be something else causing the problem/killing the module?

 

In my experience, it's been the country of manufacture, and not a problem with the car. I have a '73 Dodge pickup that still has the original forty two year old ignition module, but my '64 Valiant that was converted to electronic is already on the third module. The two failures took place within 3,000 miles, the first being intermittent, and the second catastrophic failure that melted the circuit potting material. Both were made in China, but when the last one went out I searched until I found one made in North America. It cost three times as much, but already has survived over 2,000 miles, so we shall see.

FWIW, I'm told the module must have a good ground, but if that's only for proper performance, or if it's to keep it from dying, I don't know.

 

Mopar electric moduls are a pain in the ass, sorry this aftermarket crap is it. I swaped to a hei module out of a old distrubitor in our garage, never had a problem so far and its a lot cheaper too.

 

There is nothing wrong with 4 pin Mopar modules, they are as reliable as ANY oem electronic ignition. The most common no start failure other than a dead dual ballast resistor found on the earlier 5 pin modules would be a bad pickup coil (usually a broken wire where they pass thru the distributor housing. A quick and dirty test would be to unplug the distributor and hook a volt meter to the two wires coming from the distributor-with the rotor shaft turning the pickup coil should produce enough intermitant voltage to pulse the volt meter. If there is no voltage there will never be any spark even if you hooked it up to a GM hei module.

 

I asked an old mechanic if he ever saw a Chrysler electronic ignition box fail. He said he had seen one, on an old farm truck, where the box rotted off and the guts fell out (his words).

Have heard that in hot climates they sometimes fail because of excess heat but they are a very simple, even primitive, 1970 piece of technology. Far more rugged and long lived than today's miniaturized electronics.

Go to the nearest junkyard and get OEM ones if the Chinese crap is crap.

While you are at it look in the glove compartments. Most old Dodges carried a brand new, spare ballast resistor that never got used. Grab 3 or 4 of each, and have a lifetime supply. At my favorite do it yourself junkyard all that would cost about $20 bucks.

 

What's the details on the US made one? Module was bolted on with top hole only, as I said, worked fine for a few years, added a copper ground strap (from a '84 Crown Vic) to bottom hole when I changed it out the other day.

 

Good advice Rusty. Those ballasts can fail now and then but an easy fix. Extras are the way to go. Are these Mopar electronic ignitions as dependable as a Pertronix upgrade? One of my '67 Fury's has the Mopar set up and has been good so far. I did have a starting issue but it turned out to be the connector that went to the module. $58.00 at NAPA (OUCH!) but it cured the trouble.
John

 

Over the years I've had great luck with the Chrysler electronic ignition & have run Pertronix in Fords & Mopars w/o problems.

 

Just how low was the battery? what did it read static?

 

It was low enough to spin the engine but didn't have enough juice to also supply energy to the ignition. Charged it for a number of hours & fired up the car. Drove it for a short period of time. 2 days later I'm back to no ignition. Eye dropper tester showed 4 of 5 balls floating, and the battery checked out as 99% charged today @ the store, it should start tomorrow AM when I put the new module on, but wondering why the module died (if it died) after so short a period.

 

possibly with low juice,it probably fried.... With a fresh bat,and a new module,it should start/run fine. BUT- possibly a short draining somewhere? Did the bat get low from sitting?, they usually hold a good charge for a long time unless somethings pecking at it...... stereo,clock,etc......
Did/have you checked the voltage at the bat while sitting/then cranking?
starters draw a lot of juice,even for a short period. probably something simple,but we all know how that goes......

 

have to have 9 v minimum while cranking to fire the module and the best modules for mopars are from the racing side of mopar ( Mopar performance ?? ) the second was KEM brand modules , the salvage yards around me there is a guy who raids the old OEm ones . its basically a switching transistor ( amplifier ) low voltage can screw them up but loose grounds are the biggest culprit , you should use both screws when you ground it to the chassis and make sure the ground strap between the chassis and motor are nice and clean also check the plugs for breaking wires as the older they get the more that happens

 

I try to drive it once a week, but sometimes things slide....I'll throw it back together in the AM & maybe go get the charging system checked..

 

the Mopar Performance Orange box has taken some hits in the dependability dept compared to the chrome boxes in many comments I've read. Had an orange box originally till it crapped out a few months ago after 4 years. of course the chrome box is was went tits up this time in a short period of time.

 

Lots of guys swear by Pertronix, others have had them fail. I will say I have heard of more Pertronix failures than Mopar failures, even though Mopar made about 10,000 for every 1 Pertronix.

It is more likely something other than a module failure. The pickup coil in the distributor can fail if the wire breaks from bending back and forth a million times. Wires get frayed, connections corroded, or soaked with oil. Could be a bad coil, lots of things. Impossible to say for sure without being able to test anything.

 

I would say try finding a old stock mopar box if you can . and make sure your buy a real MP part as there has been a rash of Fake counterfeits over the years . look at the package very carefully as some are almost picture perfect except spelling mistakes and other cues . here in Chicago a major distributor of them was sold a bunch of fake ones by a parts company . and it was MP/Customs who caught the sellers . ( the persons selling them to the stores imported several container loads of them and some went to other states ) the only way I would buy one is thru a MP distributor .

 

I've had Chryslers that would not start if the cranking voltage falls below 10v. Try a good battery first.

 

another possibility is the ballast resistor on these, yes they have them on electronic ign, they are 2-3 bucks you should always have a spare.

 

I had one of the 1st years the dodge Ram Chargers came out. My would fail about every 3 months. It got so bad I carried a spare one and would change it out in a few minutes when it took a dump and wouldn't start.. The truck ran like a champ though. Bruce.

 

The ballast resistor is a common failure point, more so than the electronic ignition.

By "common" I mean 1 out of 100 would burn out, after the car had 100,000 miles on it. Meaning less common than blown engines in other makes, but common for an ultra reliable Dodge.

 

Ballast Resistor check out.

 

If you still have not found the problem,pull apart the wirings plastic junction block from the harness under the dash and look for melted connections. This could give you no starts at times. The ballast resistor failure is mostly caused by a drop of cold rain water running across a hot resistor and cracking the ceramic and wire(result no start). I think they have improved the ballasts, but I solved the problem by mounting the ballast in a sardine can,apply silicone at the screw hole. (rain water cant touch it)

 

The electronic module was built at the Huntsville Alabama Chrysler plant.The ider for this unit came after the space and military programs were phased out and the plant was to close down. The designer was named Tom Lusk He came up with the design and plans in one week. Millions were produced. I have several with large heat sinks to cool the unit. Special ones were built for drag and circle track racing.

 

garyf, now that's a good idea, I remember always opening the hood on my old chevys and the water would drip down on it them and crack them.Again good idea.Bruce.

 

Sure sounds like a ballast resistor but the mention of a low battery made me think of something else. Does this car have an electronic voltage regulator? I can remember from years ago that when converting to electronic ignition, Chrysler required using their electronic voltage regulator as part of the conversion.

 

Alternator is for the electronic era cars, so voltage regulator shouldn't be a problem.

 

It has been my experience that these modules will fry themselves in short order if they have a bad or insufficient ground. Also, I've had off the rack, Chinese-made units from the parts house be bad right out of the box. I use a dedicated ground right from the box to the neutral terminal with a piece of solid 10-gauge THHN, haven't had a problem in many years.

 

I knew I remembered something about this from about 1975 when converting a '68 340 Barracuda with a mechanical voltage regulator to electronic ignition. The instructions in the Mopar kit we used specified that for older models with mechanical regulators, you also needed to change over to a later model electronic voltage regulator. If I remember correctly, the ignition module needed a steady, "clean", minimum voltage supply that you aren't like to get with a generator and mechanical voltage regulator. I seem to recall we put a Standard/Blue Streak electronic regulator on our car.

Might consider an upgrade to an alternator as well. Found this info with a little searching...

Whether you are converting an earlier ignition system, replacing Lean Burn, or repairing an existing electronic ignition system, the work is not at all difficult. Because the electronic ignition system used only a few components, it is easy to work with and troubleshoot. The requirements for installing an electronic ignition system are as follows:

• An alternator with an electronic voltage regulator.
• Electronic Control Unit (ECU).
• Distributor with a pickup coil.
• Ballast resistor.
• Wiring harness.

http://www.fourforty.com/techstuff/ignition.html

Maybe the above link to where I borrowed the above quote will help you double check your installation.

 

The import ECU's have a substandard transistor under that 'cap'. If the transistor on top has no name on it (ST or Motorola, etc) and is held on by strange looks screws, it uses a cheap smaller style transistor under that cover that has no heat sink path to the large aluminum one on top 'cept a small strap of spring metal that usually doesn't even contact the heatsink, cooks themselves. Get one that says made in USA or has ST (eg) on the transistor. And the cases need to be grounded by a star washer or dedicated strap.

 

I know this is an old post, but this MOPAR ignition test might help someone. For a no start condition where ignition is suspect: first verify that the ballast resistor is good. Best method is to use a voltmeter. I've never seen one that the resistance had gone wonky, they are either good or open circuit. Next, remove the coil wire from the distributor cap and put it near a ground. Then disconnect the 2 pin connector going to the distributor. On the loom side (vs distributor side) take the bare pin and scratch it along the intake manifold (key on). If the module and wiring are good, you should get a high voltage spark out of the coil wire as you drag the pin across the manifold. This proves the module, coil and all the associate wiring is good. If you don't get any spark with everything hooked back up while cranking, the problem is inside the distributor.