I wish I could get a look at the chrome box on the car. Some guys tore some parts store replacement boxes apart and they found: 1. That the dome that was meant to simulate the transistor was just a dummy piece of metal. 2. The heat sink was not connected to any components inside. They still operated. But sometimes die after a few weeks. When you get your multi meter, I'd be curious what you measure for the resistances on the primary ballast, and the coil. If the total is too high, you would get weak spark and if it is too low, you would burn out ignition boxes.
Glad you got it going! I lost my faith in the ECU"s ever since you couldn't get the good USA Chrysler one's anymore. I'd trust a original out of the junkyard before I would a new one.
This is were having an oscilloscope really helps out but with out one a multimeter will do. I always run a good solid braided ground the the ECU. You can check for AC voltage from the pickup at the distributor to make sure it is producing a signal and you can ohm it and it should give you a reading around 300 to 900 ohms the coil should get full voltage at cranking start... Then in run somewhere about 6 to 8 volts. Intermittent ground will kill ECUs. As well full 14 volts on stock boxes.
the efforts and money I spent on mopar ecu and coils was my mistake as it sudden fail without alarming so I replaced it with aftermarket HEI distributer and was really worth my peace
all you need for a spark test is a timing light, if you dont have anybody to turn key over while holding timing light harbor freight sells remote starter switch for $2o, if you have spark your timing light will be strobing, if you use remotr switch make sure key is in run position when checking
I think the transistor on the ECU should not be grounded like your tester showed. I still would get a volt meter and see what you voltage is. If cranking it gets real low it wont spark. Also make sure you got a good ground wire to the ECU that spliced one might have high resistance and the grounding isnt good as you think with a test light.
![No Spark Troubleshooting [Mopar Electronic Ignition with Ballast Resistor]](/img/n.gif)
I wish I could get a look at the chrome box on the car. Some guys tore some parts store replacement boxes apart and they found: 1. That the dome that was meant to simulate the transistor was just a dummy piece of metal. 2. The heat sink was not connected to any components inside.
They still operated. But sometimes die after a few weeks.
When you get your multi meter, I'd be curious what you measure for the resistances on the primary ballast, and the coil. If the total is too high, you would get weak spark and if it is too low, you would burn out ignition boxes.
Glad you got it going! I lost my faith in the ECU"s ever since you couldn't get the good USA Chrysler one's anymore. I'd trust a original out of the junkyard before I would a new one.
You're getting there!
This is were having an oscilloscope really helps out but with out one a multimeter will do. I always run a good solid braided ground the the ECU. You can check for AC voltage from the pickup at the distributor to make sure it is producing a signal and you can ohm it and it should give you a reading around 300 to 900 ohms the coil should get full voltage at cranking start... Then in run somewhere about 6 to 8 volts. Intermittent ground will kill ECUs. As well full 14 volts on stock boxes.
She’s alive👊
the efforts and money I spent on mopar ecu and coils was my mistake as it sudden fail without alarming so I replaced it with aftermarket HEI distributer and was really worth my peace
all you need for a spark test is a timing light, if you dont have anybody to turn key over while holding timing light harbor freight sells remote starter switch for $2o, if you have spark your timing light will be strobing, if you use remotr switch make sure key is in run position when checking
Check the reluctor gap and make sure that it is at .008, also check the coil and your coil wire.
What should the resistance be In ohms on a 70s Chrysler distributor?
350 to 500 ohms but sometimes they run lower and still work just fine. I've read that some run between 150-800 and have no issues.
75!!
I think the transistor on the ECU should not be grounded like your tester showed. I still would get a volt meter and see what you voltage is. If cranking it gets real low it wont spark. Also make sure you got a good ground wire to the ECU that spliced one might have high resistance and the grounding isnt good as you think with a test light.
Its freezing cold outside but ill check mine today Im curious after I slept on it.
Thanks
Omg, this is bad.