273 Electronic Ignition Issues

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MrFollmer

MrFollmer

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Ok....I had a local garage upgrade from points to electronic in the distributor cap. Replaced coil with Blaster 3, still using ballast resistor. See photo. Car stopped running, won’t fire up, a few months ago and I’m just getting around to working on it again myself. I’m an idiot when it comes to this stuff since I have no idea what I’m doing. Do I need the ballast resistor with electronic ignition? Is there a component missing in the photo that could cause this?

I just bought new wires, distributor cap, coil, ballast resistor, and plugs. Gonna redo this all in the hopes one of those items failed. But perhaps they failed because it’s wrong to begin with, not that the part failed. Can any of you gurus dumb this down for me and tell me what’s missing or what I should do differently? Motor is a ‘66 273 in a 65 Dodge Dart.

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Check the ballast first. Prob one of the installed components failed. Do the tune up after it is running.
 
Petronix?

If so, kick it to the curb.

Mine left me stranded far from home three times.
 
We need to figure out what system you have. It does not look like pertronix. The pickup looks like "factory" Mopar breakerless, introduced in the early 70's. Look around the engine room for a module, looks like this: May vary in color, be chrome, painted, etc

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With the pickup (magnetic) I see, there are only about 3 possibilities, maybe 4 for the type system you may have

1... Mopar ECU like pictured

2 &3...GM 4 pin or newer multipin module adapted

4....Some type of new aftermarket system such as MSD or others


Also it may not be wired correctly. We need to see what the ballast resiswtor (white object wired to coil) and how that is wired.

You can make some simple checks and we can step you through that. You "really need" a few basic things to troubleshoot:

1...Some type of multimeter, and in today's world, these are very easy to get and don't have to be very expensive

2.....Both an LED and an incadescant 12V test lamp. Automotive test lamp. a "real" light bulb is sometimes better because they draw some amount of current and sometimes you want that

3...If possible a couple of alligator clip jumper leads

4....Documentation. This is easy. Go to MyMopar

MyMopar - Mopar Forums & Information - MyMopar Tools/Reference

There are factory service manuals, although sometimes you must settle for Dodge vs Plymouth, etc. There are also additional wiring diagrams, as well as some "basic" diagrams showing the electronic ignition IF it is the Mopar type
 
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67Dart273 said:
We need to figure out what system you have. It does not look like pertronix. The pickup looks like "factory" Mopar breakerless, introduced in the early 70's. Look around the engine room for a module, looks like this: May vary in color, be chrome, painted, etc

View attachment 1715688069


Also it may not be wired correctly. We need to see what the ballast resiswtor (white object wired to coil) and how that is wired.

You can make some simple checks and we can step you through that. You "really need" a few basic things to troubleshoot:

1...Some type of multimeter, and in today's world, these are very easy to get and don't have to be very expensive

2.....Both an LED and an incadescant 12V test lamp. Automotive test lamp. a "real" light bulb is sometimes better because they draw some amount of current and sometimes you want that

3...If possible a couple of alligator clip jumper leads

4....Documentation. This is easy. Go to MyMopar
Click to expand...

See photos below. Tried to get multiple angles. I do have a multimeter.

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That ecu is a junk one. Prob what failed. Easy way to tell fast if it is a decent one if it has a real transistor on it or not. Also make absolutely sure the ECU is grounded. I use star washers under them to ensure this. They just used some zip screws. I would dump them put at least 1/4" sheet metal screws in and burnish the area is a good idea also.
 
halifaxhops said:
That ecu is a junk one. Prob what failed. Easy way to tell fast if it is a decent one if it has a real transistor on it or not. Also make absolutely sure the ECU is grounded. I use star washers under them to ensure this. They just used some zip screws. I would dump them put at least 1/4" sheet metal screws in and burnish the area is a good idea also.
Click to expand...

how do I tell if it has a real transistor? Photos below.

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Some additional info: it has a painless wiring kit. Not factory wires. This is honestly out of my league. I’m in finance and classic cars are a love of mine when they work as designed. I inherited this from my grandfather. Just trying to keep it alive. Should I find a shop who specializes in classic Mopars? Bouchillon Automotive is in my town and they work on old Mopars.

Another option is to simply start from scratch with quality Mopar products and the correct set up if someone has that info. It’ll scrap it all and redo it. I don’t really care about the cost, so don’t tailor your advice to saving me money. I just want it done right. I have $15k into this car and it’s worth half that (finance be damned).
 
Ill give you 5 bucks if that transistor is real! id check your cap , tht button looks a little beat.
 
pishta said:
Ill give you 5 bucks if that transistor is real! id check your cap , tht button looks a little beat.
Click to expand...
I bought a new cap. It does look a little beat. I don’t know electronics. Is the transistor the round thing with two bolts sticking out of it?
 
MrFollmer said:
I don’t know electronics. Is the transistor the round thing with two bolts sticking out of it
Click to expand...
Yes that is what it is supposed to be. Many aftermarket ECUs use other components to fire the coil and the "transistor" is only there for looks.

If you haven't yet download your FSM from mymopar.com. Classic Car Wiring . Com : Home of the original color laminated classic car wiring diagram makes some colored diagrams that are easier to follow.

Listen to 67dart273 and Mattax they know their stuff.

Once you have a wiring diagram you will have a fighting chance if figuring it out on your own.

Really dumbed down ignition system...

Ignition switch allows power to go to the plus side of the coil and the ECU, there are some paths along the way that get switched like the ballast resister and the start circuit. Ultimately the ecu and the coil will need power whenever the key is in run or start position.

The ecu acts like points, it makes and brakes a ground connection to the coil. Everytime it makes the connection to ground the coil charges up. When it brakes the connection the coil fires off a spark.

The device in the dist, is simply a switch that tells the ecu to make or brake the connection to ground for the coil.

There are so many points of failure that have to be checked, one by one. But you can do it.

Get the wiring diag and start looking at it. You can think about it like a ledger. If money comes in it has to go some where. All your money comes from the alternator, it gets saved in the battery till it is needed then it travels down the wires till it gets spent at a device.(coil, ecu, lights, radio) when you spend your money in the radio you receive sound as your valued item, spend it in the lights you get illumination, spend it in the ECU and coil you get spark.

Hope that helps a little
 
Because of the way the transistor is mounted, it is likely "fake." This is OK or bad, depending. It is simply to make the unit look "traditional." The REAL switching transistor is hidden inside. But you can not normally replace the exposed one, so ??? may not matter

You have said you are over your head. If you can round up someone with some automotive electrical experience, these systems are actually not too hard to troubleshoot.

Some basics

Start with the object at the top of the coil. Is this part of the coil, or an add-on (removeable) adaptor or resistor? If so, I'd check for spark there with "that thng" removed

If you can measure coil voltage from the coil + terminal to ground two ways.

1...Hook meter from coil+ to ground, and turn key to "run" position. Read meter. You are hoping for "somewhere" in the range of 6--10V. If voltage is higher, same as battery IE 12V then the unit is not conducting. That is bad. If it IS in that range, that's a good sign

2....Now read meter while twisting key to "start" and read with engine cranking. You are hoping for "same as battery" during cranking, you want to see at least 10.5V or more

If those two are OK, disconnect the two wire rubber connector coming out of the distributor. One end goes to distributor you do NOT want that end. Take the other end of the wire, the one going to the engine harness. The connector has a "bare" terminal. Find a ground such as the shell of the distributor, and with the coil wire rigged either near a ground, or through a grounded spark plug, repeatedly tap the bare terminal to ground. Do this with the key in the "run" position. It should make one "snap" spark each time you do this

If this is OK likely a problem in the distributor. That is the pickup/ reluctor
 
Make sure your reluctor is .008 away from the pickup. The brass feeler gauge in your flip-out set is for this. Non ferrous so it won't attract and give you a false 'drag'.
 
What the above post says about the reluctor gap. If screws were not tight, might have closed up, no spark.

The Blaster 3 coil has a very low primary resistance & may not work with that ballast res. Try & find/buy a Mopar ign coil that is matched with elec ign.
 
Easy way to tell if the transistor is real or not is if it has manufactures markings on top and is "tall" we beat them up good in here.
1974 Brain Box saves the day.

If you need any NORS parts I usually have them since I do distributors.
 
Thank you all for your advice. Check this out....(see photos)

the plug going into the ECU has 5 wires, 5 prongs on the plug. The ECU itself has four prongs. Not a rocket scientist here but shouldn’t the ECU have 5 prongs to match 5 wires?

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NO. Original design back around 71-ish had the 5th prong and used a dual ballast resistor--in other words two resistors (different from each other) in the same ceramic block. The 5 pin box had to have the dual resistor, one half being hooked to the box

The other half of the ballast goes to the coil just like a breaker points distributor. In your case, you only have a 2 pin resistor, and that goes to the coil. You have a newer 4 pin box which does not need the other resistor "half"
 
The instructions for the Mopar Performance ignition kits tell you to cut one wire off at the back of that plug, because it is unused with a 2 prong ballast resistor. If you're REALLY uncomfortable messing with all this, Bouchillon has been in business a long time, and have a good reputation. Del....aka @67Dart273 is like the air traffic controller of electrical problems around here...lol, and he can talk you thru it if you want to do it yourself.
 
67Dart273 said:
NO. Original design back around 71-ish had the 5th prong and used a dual ballast resistor--in other words two resistors (different from each other) in the same ceramic block. The 5 pin box had to have the dual resistor, one half being hooked to the box

The other half of the ballast goes to the coil just like a breaker points distributor. In your case, you only have a 2 pin resistor, and that goes to the coil. You have a newer 4 pin box which does not need the other resistor "half"
Click to expand...
Good lord...so who wants a free flight to Charleston, SC, a two day hotel stay, and a few hundred bucks to just figure it out while I watch? Ha!
 
Yes I fell into a bunch. All the NOS mopar are gone have good tested ones that are blue good to around 5500 rpm if interested.
 
MrFollmer said:
Good lord...so who wants a free flight to Charleston, SC, a two day hotel stay, and a few hundred bucks to just figure it out while I watch? Ha!
Click to expand...
These are not that bad. If you want to phone, I can step you through a few checks.
 
[FOR SALE] - 72-79 NORS ECU's | For A Bodies Only Mopar Forum

If needed send me your "bad" one i can check it fast to see if it is good. Not really a hard system to troubleshoot if you understand what each part does. The distributor pickup sends a generated AC signal to the control box and to dumb it down amplifies that signal then switches the coil on and of to spark. Assuming the wiring and ballast are good. Pretty sure you already checked that.
 
halifaxhops said:
Yes I fell into a bunch. All the NOS mopar are gone have good tested ones that are blue good to around 5500 rpm if interested.
Click to expand...
Are the blue tested ones the Chinese made junk or are these American made? Happy to buy if they'll stand the test of time. Can't send you the one I have now...just ripped it apart to confirm two things: filled with sand and the transistor is an empty shell. Was kinda fun tearing it apart with a hammer.
 
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