Sunday afternoon and no spark.... 440 6 bbl

[Sixpactogo]

Pretty sure I ran ohm meter tonight on the distributor side of the 2 wire plug although I don't remember what I found there. I don't recall there being continuity from one wire to the other though.... Is there any resistance value that I should look for from one wire through the coil and back to the other wire?

If there is no continuity between the two wires, you have an open coil

 

[Road Grabber]

If you run 12 volts to the coil to see if it starts and then pull the wire it’s not going to harm anything. That would suggest a poor voltage source and that the ECM might still be good. I don’t believe the ECM has anything to do with cranking voltage…..

This makes more sense to me because you said earlier that you didn’t have voltage to the ballast connection while cranking. That suggests ignition switch or bad connection throughout the wiring somewhere to or leaving the switch towards the ballast resistor.

You should have continuity between the two distributor plug connections. If you touch a ground from each and you get continuity there’s a short. The only thing reluctor does is break the signal.

I believe those reluctors are the same as many other Mopars. Red and black wires from the distributor?

Still waiting to hear about the ballast connection leads? What voltage readings at “start” and “run” ? The ignition switch should send full voltage while cranking to the resistor.

I have had bad ECMs and also bad ignition switches too but I would first see if the switch is getting the 12 volts on the source side and sending the same out to the ballast resistor via ballast connection before changing the switch. The do go bad and the under dash connection for the column gets corrosion. You could back probe the connector to the ignition switch under the dash to check voltage in and out. It could be fine on one side but low on the other because or a bad connection.

The easiest test first without crawling under the dash is to test the ballast connections first.

 

[P Dubya]

Sooooooooo,

What voltages are you getting to the two ballast leads in start and run positions?

View attachment 1632747

View attachment 1632748

Sooooooooo,

What voltages are you getting to the two ballast leads in start and run positions?

View attachment 1632747

View attachment 1632748

L1/green Key in run position. Zero to .66 volts.
L2/red key in run position has full battery voltage. Drops to 9.5V or so when cranking.
Top connector into resistor is blues wires

 

[P Dubya]

If there is no continuity between the two wires, you have an open coil

Definitely no continuity between the 2 wire that go into the distributor to the pickup coil.

 

[P Dubya]

This one is showing continuity to ground.

 

[Road Grabber]

I don’t have a schematic in front of me but I think you are testing the wrong plug. One of the connectors should have two wires connected together and those blue wires only have one at each plug end.

I would recommend checking with an electronic ignition wire diagram to make sure the ballast wiring is correct. Make sure they are at the correct end of the resistor too.

Also confirm the plug connections you are testing are the ignition 1 and ignition 2 connections. From the picture it doesn’t look right to me.

You may have things mixed up?

 

[Road Grabber]

You have two wires on the ignition 2 end

I didn’t see a diagram with a color code wire

 

[dadsbee]

Not a correct wiring diagram for a 4 pin ECU...

 

[Road Grabber]

Is this confirmed a four pin? I haven’t seen a picture.
Either way it looks like the two wire connection - brown and blue together would be the ignition 2 to check cranking voltage

It would be at least a good idea to confirm

 

[dadsbee]

Post #12... clear as a bell.

 

[Geoff 2]

The magnetic pick up inside the dist. If the vac adv was hooked up & working, the p/up wires will eventually break because the wires flex every time the vac adv moves. Disconnect the plug & measure the resistance, should be 100-500 ohms; flex the wires while measuring checking for an open circuit.
If vac adv is NOT hooked up, unlikely that the p/up has failed, but it is possible.

 

[Road Grabber]

Looking back at the test you did at the distributor plug. There is a problem. I think the magnetic pickup too.
You can move the wires around and see if you get different results because of a short or break. Most likely in the bend like suggested above post or check where the wires come through the housing to see if a wire is grounded to the casting.
I have seen it a couple times that the pickup wires.
Easy enough to note the rotor position and just remove the distributor rather than drop something inside the distributor.

 

[P Dubya]

Is this confirmed a four pin? I haven’t seen a picture.
Either way it looks like the two wire connection - brown and blue together would be the ignition 2 to check cranking voltage

It would be at least a good idea to confirm

It is a 4 pin ECU.

 

[P Dubya]

Looking back at the test you did at the distributor plug. There is a problem. I think the magnetic pickup too.
You can move the wires around and see if you get different results because of a short or break. Most likely in the bend like suggested above post or check where the wires come through the housing to see if a wire is grounded to the casting.
I have seen it a couple times that the pickup wires.
Easy enough to note the rotor position and just remove the distributor rather than drop something inside the distributor.

I have ordered a new pickup coil assembly. I can not get any continuity through the 2 wire plug at the distributor nor resistance through the coil inside the distributor. Lots of movement in the wires made no changes....

 

[P Dubya]

The magnetic pick up inside the dist. If the vac adv was hooked up & working, the p/up wires will eventually break because the wires flex every time the vac adv moves. Disconnect the plug & measure the resistance, should be 100-500 ohms; flex the wires while measuring checking for an open circuit.
If vac adv is NOT hooked up, unlikely that the p/up has failed, but it is possible.

No resistance through wires/coil could be found. Twisted/moved wires quite a bit during testing with no change.

 

[RemCharger]

For laughs I measured 4 pickups,
233
238
273
280

 

[P Dubya]

For laughs I measured 4 pickups,
233
238
273
280

Thank you! Looks like I may be heading in the right direction. Not to say that there isn't other problems but the pickup coil sure seems to be one of them. Wish I had a stash of them in my garage!

 

[Road Grabber]

I was told by a member that all the red/black pickups were the same no matter the application.

 

[Road Grabber]

The magnetic pick up inside the dist. If the vac adv was hooked up & working, the p/up wires will eventually break because the wires flex every time the vac adv moves. Disconnect the plug & measure the resistance, should be 100-500 ohms; flex the wires while measuring checking for an open circuit.
If vac adv is NOT hooked up, unlikely that the p/up has failed, but it is possible.

I wondered why that happens. Makes perfect sense. Thanks for that information.

Throwing a few more things in the trunk might be a good idea like an extra pickup, voltage regulator, ECM etc.

 

[Sixpactogo]

The Pickup coil was my first thought. I have had a couple of them fail over the years. All of them worked fine while driving. They both failed after a shut down and attempt to re-start. Always when I was not close to home. I have only one spare. It tested at 299 ohms. They are a coil so just like any other, they can fail.