No Spark help

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Pumpkinduster

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Just finished installing my 318 into the 1974 Duster (/6 originally).
Tonight we decided to try a test start to see where we are and there is no spark. I have test with a spark plug to the #1 plug wire, as well as I tested a spark plug from the coil plug on the distributor neither have spark.

I have a 5 pin ECU with a double ballast that all ran before I pulled the /6. Can someone tell me if I am missing something or have something wrong.

I tested the Ballast the top 2 pins are reading 5.5 Ohms and the lower 2 are 1.4 Ohms so that is still good.

My coil is testing post to post 1.6 (recommended .75 to .81) and positive to coil pick up 8.1 on a 20K reading (recommended 10k-11k) So I am going to replace the coil for sure.

My question is since the car already had the electronic ignition what do I need to add or change for the 318. I have attached pics, but the 318 had a small ballast on the coil mounting point - Is this still needed? This tested at .3 Ohms but cant find any recommended numbers for it.

Also on the opposite side it looks to have an isolator for the negative side?

The current wiring is below:
Alternator has blue and green wire - Both run to the voltage regulator. Blue wire continues to the small Ballast.
The other side of the the small ballast has a brown / white stripe coming from what looks like the firewall connections (I can better trace it tomorrow if needed)

Coil
Negative has a black /yellow stripe that connects to the ECU, as well as the black wire running to the isolator.

Positive has a solid brown wire that runs back to the engine harness connector. (haven't traced that one yet either)

Should I be getting power to the coil once the ignition is on? Would this be tested just off of volts from post to post of the coil?

Also is there any additional wires I am missing? Like from positive to small ballast and negative from coil to distributor body? I only ask because it have seen it both ways on different diagrams.

Let me know if you need more specific pictures as well. Thank you and I'm stoked to get this guy fired up and broken in soon.

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OK That small ballast is for the choke, the condenser is for noise suppression for the radio. Just noticed you have the seatbelt interlock shown in pic 2 might be as simple as resetting that button (the metal box just above the ecu)
 
OK That small ballast is for the choke, the condenser is for noise suppression for the radio. Just noticed you have the seatbelt interlock shown in pic 2 might be as simple as resetting that button (the metal box just above the ecu)
Good to know. if the ballast is for the choke, I have an electric choke now, can it be removed? What should happen with the two wires that are going to it currently? Blue and a brown one connected to it.
I will look at how to reset that one as well.

Thank you
 
Ok here is an update. I have pulled the three prong plug off of the seat belt interlock as well as disconnected the plugs under the seats. It feels like it is trying to start now. My next question is how much voltage should I have at the coil with the ignition on? I am reading 4 volts post to post with the key one.
 
Ok I have replaced the cap, rotor, coil, ballast resistor and still no spark. What am I missing?
 
Ok I have tried and tested everything I can. I have been cross referencing a couple diagrams as well as my book (book only goes to 72 for wiring). In the picture there is a tan wire that runs to the engine harness connector. The end of the tan line is a female connector and it is getting 10 volts with the key on. The other two are the blue wire coming from the alternator and alternator regulator, any idea where this should be connected too? It currently is going into the engine harness connection from both alternator and regulator then to the ballast. The brown and white wire as no power to it with the key on and runs back to the bulkhead connector on the firewall.

Can anyone help pin point where these 3 wires should go? I pulled them off the small ballast already.

Also the the condenser next to the coil should it go to the positive or negative post? My picture from disassembly looks like the positive but that doesn’t make sense to me.


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OK That small ballast is for the choke, the condenser is for noise suppression for the radio. Just noticed you have the seatbelt interlock shown in pic 2 might be as simple as resetting that button (the metal box just above the ecu)
I can’t seem to find anything relating to that being a radio condenser, why would it connect to the coil? And if it is supposed to should it be on the positive terminal or negative?
 
Feel like I am talking to myself here.
I have continued to test and test with no change. The wire running to the positive side of the coil is only reading 10 volts, but once it is connected to the the the coil the voltage drops to 3.45 and .13 on the negative side.

I tested the voltage at the ballast and got the following with the key in the run position:

Upper Left = 10 volts
Lower Left = 9.9 Volts
Upper right = 2 volts
Lower Right = 3.7 volts

At this point I am lost any ideas on what to test next or what to look into. I have double checked my wiring and it looks like it should be compared to the FSM.
20190608_101229-jpg.jpg


I am going to try to add an addition ground to the ECU.
Also I am trying to understand the Ballast jumper idea. Would I just be running a wire from my battery positive to the upper left of the ballast with the plug still connected to force the battery voltage to the coil. Am I understanding that right?
 
I can’t seem to find anything relating to that being a radio condenser, why would it connect to the coil? And if it is supposed to should it be on the positive terminal or negative?
Dug deeper and found what I needed for this part. Thank you
 
Any input? Still no spark is there any other test I can try to get this to fire up? I’m now at a loss
 
With nothing running, voltage at the ignition terminals on the ballast resistors should be the same at the battery voltage.
I have a 5 pin ECU with a double ballast that all ran before I pulled the /6
My question is since the car already had the electronic ignition what do I need to add or change for the 318.
Shouldn't. There may be small differences due to emissions related devices (like the timing device mentioned above that operational schematic)

I tested the Ballast the top 2 pins are reading 5.5 Ohms and the lower 2 are 1.4 Ohms so that is still good.

My coil is testing post to post 1.6 (recommended .75 to .81) and positive to coil pick up 8.1 on a 20K reading (recommended 10k-11k) So I am going to replace the coil for sure.
The coil windings and the ballast resistor are matched pair. So if the '74 FSM says ballast resistor should be 1.4 Ohms and the coil primary .75, then yes change coil.

I have attached pics, but the 318 had a small ballast on the coil mounting point - Is this still needed? This tested at .3 Ohms but cant find any recommended numbers for it.
Hoppy answered that. Sketch it out and see how it operates. Since your using an electric choke it may be useful. If you've hooked up your electric choke so that its drawing off power, that could be your issue.

Alternator has blue and green wire - Both run to the voltage regulator. Blue wire continues to the small Ballast.
Blue wire supplies power to the alternator's field windings (rotor). It is used by the voltage regulator to sense system voltage and decide what to do. Blue wire should always be at system voltage when the key is in Run position.

Coil
Negative has a black /yellow stripe that connects to the ECU, as well as the black wire running to the isolator.
The ECU does the same as points. It opens and closes the primary circuit. When its closed, current flows through the coil inducing a high voltage charge to be developed in the secondary side. When it opens the flow stops and the high voltage charge goes to the distributor.

Positive has a solid brown wire that runs back to the engine harness connector. (haven't traced that one yet either)
It should connect to the ignition circuit.

Should I be getting power to the coil once the ignition is on? Would this be tested just off of volts from post to post of the coil?
There should always be power present at the coil positive when the key is in Run or Start. The voltage at the coil positive will vary depending on whether its flowing and whether its coming through the resistor (run) or direct (start).

When the engine is running, the alternator supplies power that is regulated to be around 14 Volts.
When current flows through the compensating resistor, the voltage drops a little. A little more when hot. Reducing the voltage keeps the coil from overheating.
In Start, the battery supplies voltage around 11 Volts or less, so no compensation is needed.
This might clarify that operational schematic.
upload_2019-6-25_8-22-55.png


In the back of the Electric section of your 74 FSM is the wiring diagrams. Use those figure out the connections.
 
With nothing running, voltage at the ignition terminals on the ballast resistors should be the same at the battery voltage.


Shouldn't. There may be small differences due to emissions related devices (like the timing device mentioned above that operational schematic)


The coil windings and the ballast resistor are matched pair. So if the '74 FSM says ballast resistor should be 1.4 Ohms and the coil primary .75, then yes change coil.

Hoppy answered that. Sketch it out and see how it operates. Since your using an electric choke it may be useful. If you've hooked up your electric choke so that its drawing off power, that could be your issue.

Blue wire supplies power to the alternator's field windings (rotor). It is used by the voltage regulator to sense system voltage and decide what to do. Blue wire should always be at system voltage when the key is in Run position.


The ECU does the same as points. It opens and closes the primary circuit. When its closed, current flows through the coil inducing a high voltage charge to be developed in the secondary side. When it opens the flow stops and the high voltage charge goes to the distributor.

It should connect to the ignition circuit.

There should always be power present at the coil positive when the key is in Run or Start. The voltage at the coil positive will vary depending on whether its flowing and whether its coming through the resistor (run) or direct (start).

When the engine is running, the alternator supplies power that is regulated to be around 14 Volts.
When current flows through the compensating resistor, the voltage drops a little. A little more when hot. Reducing the voltage keeps the coil from overheating.
In Start, the battery supplies voltage around 11 Volts or less, so no compensation is needed.
This might clarify that operational schematic.
View attachment 1715354889

In the back of the Electric section of your 74 FSM is the wiring diagrams. Use those figure out the connections.


Thank you. Unfortunately the Chiltons manual even though it’s for up to ‘76 only going to 72 for wiring . I have found a few other diagrams to work off of.

Right now the issue looks to be when I add the hot wire to the coil I have 10volts but as soon as it’s on the coil it drops to 4 volts even under crank. We are going to try a new ECU after work. I have tested the black and yellow wire back to the ECU and verified it has continuity.

I’ve sanded the area the bolts hold the ECU front and back as well as made dual grounds that return to the battery to make sure I have solid ground at the ECU. I’m going to also try to add a jumper straight to the coil + and jump the starter wires to see if there is any spark, this should help determine if it’s the ignition itself right?
 
Start and Run are differnet routes.

Voltage drops when current is flowing through resistance. When there's no flow, the resistance goes away. The poor connection of course hasn't gone away, but its not causing any resistance because there's no flow. If your seening voltage drop through anything other than a resistor then two things are happening.
1 Current is flowing so so there's a connection from positive to ground. That shouldn't happen at the coil when the key is off.
2. There's high resistance in the circuit between the two voltages. Find where it drops and you've found the resistance.

You made one electric change, the electric choke. I'd suspect that first.

Some Chilton's are sometimes useful but not for stuff like this.
Bishko sells reprints.
There's also thread on FABO with a title something like Free Manuals.
I know there's a '73, I don't know about a '74.

I don't know if disconnecting the interlock wires was the correct move. Do a search on that.

I would not leap to connecting the coil directly to the battery. That's a bit risky and desperate move IMHO.

It could be as simple as one of the terminals backed out of its connector.

PS. When you see a voltage drop and the power is coming from the battery, glance at the ammeter. It shows approximately how much current is flowing out of the battery (except what goes to the starter). It should be pretty small current 2 to 5 amps for starting.
 
PS. I assumed its just for the photo but the coil's secondary wire looks loose.

If you find there's voltage drop before the ballast resistor you can quickly check for where the resistance may be.
Check the voltage at the alternator output stud. Since there's no current in that line, it should be at battery voltage.

Turn the key off and turn the parking lights on. Check again for voltage drop at the alternator. If there is check at the bulkheads.
if not sure, turn the headlights on.
This will indicate if the resistance is before or after the ignition switch. If there's noticble drop with the lights on, key off, then the problem(s) is before the ignition switch.

To measure voltage drop you must measure the voltage at the source when the current is flowing (at the battery when things are turned on). Then at different points downstream. You can measure the drop directly or you can measure from ground if you are confident the grounds are good.
 
Start and Run are differnet routes.

Voltage drops when current is flowing through resistance. When there's no flow, the resistance goes away. The poor connection of course hasn't gone away, but its not causing any resistance because there's no flow. If your seening voltage drop through anything other than a resistor then two things are happening.
1 Current is flowing so so there's a connection from positive to ground. That shouldn't happen at the coil when the key is off.
2. There's high resistance in the circuit between the two voltages. Find where it drops and you've found the resistance.

You made one electric change, the electric choke. I'd suspect that first.


Some Chilton's are sometimes useful but not for stuff like this.
Bishko sells reprints.
There's also thread on FABO with a title something like Free Manuals.
I know there's a '73, I don't know about a '74.


I don't know if disconnecting the interlock wires was the correct move. Do a search on that.


I would not leap to connecting the coil directly to the battery. That's a bit risky and desperate move IMHO.

It could be as simple as one of the terminals backed out of its connector.


PS. When you see a voltage drop and the power is coming from the battery, glance at the ammeter. It shows approximately how much current is flowing out of the battery (except what goes to the starter). It should be pretty small current 2 to 5 amps for starting.

My slant 6 was already wired with an electric choke, but the 318 I bought still had the resistor for the choke, that's the only reason it was carried over. Could I keep that as is and use it to go to the electric choke? Right now it would have my dark blue wire connected to it (hot wire), but then I have a brown wire that runs back to the bulkhead connected to the other side of it. I'm not %100 what the brown wire feeds until I can get a more accurate diagram. But my thought was keep the blue there and make a jumper to my electric choke, is that ok to do?

I have since reconnected and reconnected the under the seat connections as well as reset the unit. (the car ran fine before the motor swap with the interlock so no need to take it out yet)
So far I have pulled all the bulkhead connectors and made sure they were as clean as I can get them as well as pushed as far forwards. I did this as well with the engine harness connector and the interlock connector.

I will give this a try when I am off work. Also whats the thoughts on the ECU being the issue? I have been reading that can be a big part of the issue. Would it be worth it to pick a new 5 pin up just incase?
 
Quick lesson in electric circuit.

Key off, lights off, all of the uninterupted wires connected to the battery will be at battery voltage.
Measure voltage at any of those connections or wires and they will be at battery voltage.
If we put a test light in the line, it won't light up because there is no current flowing.
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Turn on the parking lights, and the current flows through the test lamp and eventually back to battery ground.
If the test lamp and parking lamps draw 5 amps the flow path will look like this.
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Since there's no flow in the alternator's output circuit, it acts like an expension of the probe.
We can be pretty sure its 12.0 Volts at the bulkhead connector and the main splice. The first is relatively easy to check directly, the main splice is not.

Then the question is where is .3 Volt drop coming from?
In this example it might very well be the test lamp.
Measuring the drop directly shows that is majority of the resistance.
upload_2019-6-25_13-58-59.png
 
My slant 6 was already wired with an electric choke, but the 318 I bought still had the resistor for the choke, that's the only reason it was carried over. Could I keep that as is and use it to go to the electric choke? Right now it would have my dark blue wire connected to it (hot wire), but then I have a brown wire that runs back to the bulkhead connected to the other side of it. I'm not %100 what the brown wire feeds until I can get a more accurate diagram. But my thought was keep the blue there and make a jumper to my electric choke, is that ok to do?
Not sure what you're saying about the choke resistors. The '73 diagram doesn't show any difference in wiring for a six vs an 8.
It only needs, and only should get power when the engine is running. In fact all it does is speed up the choke opening - my recollection is there still was a mechanical (bimetal coil) choke on the intake. Maybe I'm wrong it its an electric only deal. Regardless, it only gets power when the engine is running. There should be a control switch then the resistor and then connects to the choke heater.

Blue wires are usually from ignition 1(run).
Brown wire to the ballast resistor is usually from ignition 2 (start).
For '73 and sounds like '74 as well, the coil feed wire is also brown.

In Start - brown to the ballast should be battery voltage.
In run - blue to the ballast should be system voltage (either battery or alternator - whichever is higher)
 
Quick lesson in electric circuit.

Key off, lights off, all of the uninterupted wires connected to the battery will be at battery voltage.
Measure voltage at any of those connections or wires and they will be at battery voltage.
If we put a test light in the line, it won't light up because there is no current flowing.
View attachment 1715354986

Turn on the parking lights, and the current flows through the test lamp and eventually back to battery ground.
If the test lamp and parking lamps draw 5 amps the flow path will look like this.
View attachment 1715354994


Since there's no flow in the alternator's output circuit, it acts like an expension of the probe.
We can be pretty sure its 12.0 Volts at the bulkhead connector and the main splice. The first is relatively easy to check directly, the main splice is not.

Then the question is where is .3 Volt drop coming from?
In this example it might very well be the test lamp.
Measuring the drop directly shows that is majority of the resistance.
View attachment 1715354995

Ok this is going to drive me nuts.
Ignition off and nothing extra connected ( i dont have a test light to use in between the battery to starter relay)

Battery to pos to ground showed 12.77 volts, and alternator post to ground 12.77 volts with ignition off and nothing extra connected.

Parking lights on:
Battery 12.72 volts
Alternator 12.67

I did see the the gauge drop a little.

So I pulled the engine harness connection and tested there instead of alternator. key off and lights off
Battery = 12.77
Connector = 12.72

Next I followed the connection back to the bulkhead.
I pulled the connections and verified it was clean, ran some sand paper over the males again. Reattached the bulkhead and tested at the engine harness again.
Battery = 12.77
Harness = 10.68 (WTF)

Next I pulled the fuseable link and tested there.
Battery = 12.77
Fuseable link =12.77 (at the bulkhead male connection)

Reconnected bulkhead again and probed, at the bulkhead, the wire to the alternator engine harness
Wire = 10.68

So somehow in the process of locating the issue I have made things worse :(

The thing I don't understand is no connections were removed from the engine bay when I pulled the /6 other then then engine harness connection and the transmission neutral safety switch.
What is going on? It's like the car is rejecting the awesomeness of the new motor lol. Sorry my brain is numb so I need humor.
I will have to start looking under the dash too.
 
Ok this is going to drive me nuts.
Ignition off and nothing extra connected ( i dont have a test light to use in between the battery to starter relay)
Don't need one. In this case it was just to illustrate current flowing.
A light can be useful when hunting a short to ground.
Since there is an ammeter in that line, it also shows whether current is flowing. So it does the same thing.

Parking lights on:
Battery 12.72 volts
Alternator 12.67

I did see the the gauge drop a little.

So I pulled the engine harness connection and tested there instead of alternator. key off and lights off
Battery = 12.77
Connector = 12.72
Essentially very little drop in voltage for an approximately 5 amp draw.
from this it would seem there's no problem from battery to main splice.

Next I followed the connection back to the bulkhead.
I pulled the connections and verified it was clean, ran some sand paper over the males again. Reattached the bulkhead and tested at the engine harness again.
Battery = 12.77
Harness = 10.68 (WTF)

Next I pulled the fuseable link and tested there.
Battery = 12.77
Fuseable link =12.77 (at the bulkhead male connection)

Reconnected bulkhead again and probed, at the bulkhead, the wire to the alternator engine harness
Wire = 10.68

So somehow in the process of locating the issue I have made things worse :(

The thing I don't understand is no connections were removed from the engine bay when I pulled the /6 other then then engine harness connection and the transmission neutral safety switch.
What is going on? It's like the car is rejecting the awesomeness of the new motor lol. Sorry my brain is numb so I need humor.
I will have to start looking under the dash too.

Assuming you had the parking lights on when you made that last probing. Then yes, it would seem that the problem is between the bulkhead connector and the main splice. Since the only things you were touching were the connector (or connectors?) it is likely something loose right at the connector. Such as either terminal (the metal part) slipping out of the connector when you put them together Or could be wires broken at the terminal's crimps.
 
The male terminals usually hold in better, but if they do back out, or you've removed them, this is the barb that retains them.
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The female terminals have a barb on the backs.
Your bulkhead connector may look different but the terminals work the same way.

If they look like this they are Chrysler style, Packard 58
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If they look like the ones below, they are Packard 56 series.
Both install the same way. Sometimes they are interchangable. Sometimes not and they won't fit in or they will be too loose in the connector made for the other.
When installing the females make sure the locking tab is raised.
To remove the females, use a flattened cotter pin, tiny screw driver, or the tool they make for it to depress the tab while pushing it out.
factoryterminal01-gif-gif.gif


If there is a problem at the crimps, then a crimper for 'open barrel' terminals is needed to fold the wings in properly when replacing.
factoryterminal03-gif-gif.gif

(above 2 pics borrowed from civilianjeep bb: BASIC WIRING 101, Getting You Started! - JeepForum.com)
 
Also the the condenser next to the coil should it go to the positive or negative post? My picture from disassembly looks like the positive but that doesn’t make sense to me.
Positive.

From the 1973 Dodge Chassis Manual.
upload_2019-6-26_7-59-26.png


For the choke control the wire colors are different than you have (blue and black) so obviously different than '74.
 
Don't need one. In this case it was just to illustrate current flowing.
A light can be useful when hunting a short to ground.
Since there is an ammeter in that line, it also shows whether current is flowing. So it does the same thing.


Essentially very little drop in voltage for an approximately 5 amp draw.
from this it would seem there's no problem from battery to main splice.



Assuming you had the parking lights on when you made that last probing. Then yes, it would seem that the problem is between the bulkhead connector and the main splice. Since the only things you were touching were the connector (or connectors?) it is likely something loose right at the connector. Such as either terminal (the metal part) slipping out of the connector when you put them together Or could be wires broken at the terminal's crimps.


This was with the ignition off after I pulled the bulkhead. I will pull them and check the connections again today.
Thank you for all the help btw
 
This was with the ignition off after I pulled the bulkhead. I will pull them and check the connections again today.
My point was any voltage drop should only occur when there is current flowing. So something was on or there is a short or just a bad measurement.
 
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