Electronic Ignition System Issues
#3222885
03/26/24 01:01 PM
03/26/24 01:01 PM
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Joined: Feb 2005
Posts: 74 Sin City
calif67rt
OP
member
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OP
member
Joined: Feb 2005
Posts: 74
Sin City
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First let me clarify that I know very little about electronic ignition systems and car electrical systems except they are needed to run the car. 1967 Dodge Coronet R/T, 440HP engine converted to a Chrysler electronic ignition system. This was done more than 30 years ago before I bought the car. The ignition system worked fine for many years but over the last few it has given me fits. What is happening is that I am not getting spark to the coil so it won't start. When I turn the ignition switch off the engine kinda of "thumps" as if it got an instant spark and it feels like it is trying to turn the motor backwards. Occasionally it will start when I release the starter but very seldom. The magnetic pickup in the distributor was replaced several years ago. It now has an MSD coil. The ecu was replaced a couple of weeks ago as it was fried due to the it receiving 17 volts (per the mechanic). He replaced a wire from the voltage regulator to the ballast resistor and the car started and ran fine for a while. He said the alternator was working fine and putting out the proper voltage. But last weekend it wouldn't start again. It also had a brand new battery in it. Does anyone have any idea what is going on and suggestions on how to fix it? Thanks in advance for your input. I has always helped me in the past and is much appreciated as I love my Mopars but don't always know how to fix them. Bill
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Re: Electronic Ignition System Issues
[Re: calif67rt]
#3222903
03/26/24 01:50 PM
03/26/24 01:50 PM
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Joined: Jan 2003
Posts: 17,846 S.E. Michigan
ZIPPY
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 17,846
S.E. Michigan
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Usually it's a wiring problem involving the start and run circuits, all the way to the ballast and ECU, all the way to the coil.
Determine if you have 2 or 4 pin ballast, pull a wiring diagram from online and ensure it's wired as it should be. Look for hack temporary repairs (wires twisted and taped together and so on).
Assuming a 727, pull the yellow wire on the starter relay to the neutral safety switch so the starter won't crank, turn the key to "start" and check coil + voltage. Then check battery voltage across the two terminals. The two numbers should be basically the same. If the voltage at the coil is non existant or substantially lower, there's definitely a wiring problem, bad connection, failed switch but wiring/connection problems are most prevalent. Use a digital multimeter. If you don't own one, definitely buy one, it will help you a bunch.
Rich H.
Esse Quam Videri
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Re: Electronic Ignition System Issues
[Re: calif67rt]
#3222912
03/26/24 02:37 PM
03/26/24 02:37 PM
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Joined: May 2019
Posts: 6,262 nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,262
nowhere
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As Zippy said, you have a wiring problem.
In NORMAL operation,
While running the ignition switch powers the run circuit which powers the coil through the ballast resistor.
While starting the ignition switch powers the start circuit, this bypasses the ballast resistor and powers the coil with full battery voltage to improve starting. You are not getting this voltage at the coil.
As a quicky confirmation, run a jumper wire from the battery + to the coil + and see if it starts.
The "bump" you are feeling happens when you release the key and the run circuit powers up letting the coil spark. It's not enough to actually start the car though.
Since this is an add on system the stock wiring diagram may or may not help.
The ballast resistor plays no part in the start circuit, any suggestions that this is the problem are given by those who do not know how the ignition system works, The closest it gets to being involved is being a place for the wires to connect. The fact that you are getting the "bump" as you call it tells us the ballast is ok.
I dug out my 67 FSM.
The STOCK wiring colors and what they do are as follows.
At the ballast
Dark Blue goes to the coil, this is the coil power lead in start and run Brown hooks to the same side of the ballast as the Dark Blue wire above, this is where the voltage to power up the coil in START comes in ans is probably what is missing. This wire goes thru the bulk head connector ti the IGN2 terminal on the ignition switch.
On the other side of the ballast you have one wire, a Dark Blue one. This one provide voltage to the ballast in RUN, the power goes thru the ballast to the coil, again in RUN. The Other end of this wire goes to the IGN terminal on the mechanical voltage regulator.
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Re: Electronic Ignition System Issues
[Re: calif67rt]
#3222919
03/26/24 02:47 PM
03/26/24 02:47 PM
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Joined: Jan 2003
Posts: 25,817 Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,817
Rio Linda, CA
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Disconnect the engine harness connector at the distributor, turn on the ignition switch and touch the male prong on the engine harness to ground. Each time the prong is grounded and pulled away you should get a spark from the coil. If it sparks, the distributor pickup is the problem, if not it's the primary wiring, ECU or coil.
The INTERNET, the MISinformation superhighway
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Re: Electronic Ignition System Issues
[Re: Sniper]
#3222946
03/26/24 05:39 PM
03/26/24 05:39 PM
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Joined: Jan 2003
Posts: 32,934 Grand Prairie,Texas
stumpy
I Win
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I Win
Joined: Jan 2003
Posts: 32,934
Grand Prairie,Texas
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The starter relay plays no part in the ignition system. He is saying jump the relay to crank the engine with the ballast hooked to battery power.It's eaiser then having to reach in to turn the key. He isn't saying the relay is part of the ignition.
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Re: Electronic Ignition System Issues
[Re: fastmark]
#3223036
03/27/24 08:30 AM
03/27/24 08:30 AM
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Joined: May 2019
Posts: 6,262 nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,262
nowhere
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Sounds like a bad ballast resistor to me. As stated. Put the key in the run position and I use a starter switch as a jumper. Put one lead on big terminal of the starter relay and the other smaller screw with hex head slotted screw. It should start right up if it’s the ballast resistor is bad. Most carry those as a spare. They go out all the time. You can jump those two post with a screw driver or pair of pliers in a pinch. It just engage starter is all. I will reiterate, anyone that states the issue in this situation is the ballast knows nothing about how mopar electronic ignitions work. It is bypassed in start, The OP gets a bump when he releases the key and it returns to run, that tells you right there the ballast is ok.
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Re: Electronic Ignition System Issues
[Re: Sniper]
#3223062
03/27/24 10:48 AM
03/27/24 10:48 AM
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Joined: Jun 2005
Posts: 670 NY
twodoorpost
mopar
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mopar
Joined: Jun 2005
Posts: 670
NY
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Corrosion in the connector from the distributor to the wiring harness. Unplug it and clean the contacts and try it. This has worked for me in the past. Sometimes just unplugging it and plugging it in again scratches the corrosion and the remakes the connection, but it doesn't last long.
Last edited by twodoorpost; 03/27/24 11:00 AM.
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Re: Electronic Ignition System Issues
[Re: Sniper]
#3223088
03/27/24 11:39 AM
03/27/24 11:39 AM
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Joined: Feb 2005
Posts: 528 SW CO
HemiSportFury
mopar
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mopar
Joined: Feb 2005
Posts: 528
SW CO
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Sounds like a bad ballast resistor to me. As stated. Put the key in the run position and I use a starter switch as a jumper. Put one lead on big terminal of the starter relay and the other smaller screw with hex head slotted screw. It should start right up if it’s the ballast resistor is bad. Most carry those as a spare. They go out all the time. You can jump those two post with a screw driver or pair of pliers in a pinch. It just engage starter is all. I will reiterate, anyone that states the issue in this situation is the ballast knows nothing about how mopar electronic ignitions work. It is bypassed in start, The OP gets a bump when he releases the key and it returns to run, that tells you right there the ballast is ok. Yep. A bad ballast is just the opposite, starts and then immediately dies. I had that happen late one night on the way home. Engine kept dying. I'd have the shift to neutral (auto) and restart it. It would run briefly then die. One time I hit start before I put it in neutral and it refired. So I just held it in start position until I got home.
'64 Sport Fury, 528 Hemi, FiTech EFI, 4-speed, 4.10 Dana 60 '57 Belvedere 2dr sedan, current project in process '19 Cherokee Trail Hawk Elite '03 Ram 2500 CTD HO, 6-speed 214,000 miles and still going strong
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Re: Electronic Ignition System Issues
[Re: ThermoQuad]
#3223109
03/27/24 12:17 PM
03/27/24 12:17 PM
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Joined: Jan 2003
Posts: 25,817 Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,817
Rio Linda, CA
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Check the distributor pickup by using an ohm meter across the connector. I do not remember what it is supposed to read but it is simple ohms.
Set your meter on ohms and read between the two wires on the pickup, should read around 300-900 ohms. Then set the meter on the lowest AC volts and measure the voltage from the pickup when a reluctor blade passes the pickup, should read slightly less than 1 volt.
The INTERNET, the MISinformation superhighway
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