1974 Dart 318 crank, but no start (Solved)

[Rhino_74Dart]

***SOLVED*** Wire from ICM/ECU to Negative side of coil was broken right at crimp, but rubber sleeve held it in place without allowing voltage to pass thru.

I know this issue has been beat to death, I've read the posts, watched the videos, and I'm still stumped.

1974 Dart, 318 w/electronic ignition. I drove the car into my garage before tearing it apart, engine was jerry rigged to run stand alone, no ign. switch involved. I just finished rewiring the entire car with AAW kit for A body. It cranks real strong, but will not fire.

Have orange box ICM that was new to get car running. what appears to be factory dist./pickup coil, new coil, new ICM wiring.

I get battery voltage to ballast resistor, both sides, with key on. Don't know if ballast is bad, or because current is not flowing, I have tried 2 different ballasts and both read full voltage on both sides.

I get batt. volt. to + and - sides of coil, and test light only dims while cranking, does not flicker.

ICM box is fully grounded to body, only way to ground more is to weld it.

With ICM harness unplugged, or plugged in, voltage at coil or ballast does not drop. A video said the ICM being plugged in should drop the voltage at coil.

I have quadruple checked connections, and cannot find anything amiss.

I don't have an extra dist., I don't want to remove dist. from engine as it ran to get into garage.

I don't have an extra ICM to swap out, and don't want to throw parts at it. Only part of ignition that isn't new is the dist. and internals.

Wiring is done per AAW, brown wire, Ign. 2 goes to coil +, pink, ign. 1 goes to ballast, along with blue wire from ICM, black ICM wire goes to coil -, green 5th wire is not used, other 2 go to dist.

White tach wire goes to bulkhead, but is not connected, and I have tried disconnecting it, does not help.

Pulled cap, cleaned reluctor and pickup coil contacts, new cap, rotor, plugs and wires.

I don't know how to reliably test dist. pickup, or the ICM to know which part, if any, needs replacing.

 

[Professor Fate]

If it is a true '74 replacement harness, it has the dreaded '74 only seat belt interlock system. It won't fire if the interlock is missing, or the module has tripped and has not been reset. Most people eliminate or bypass the system.

 

[Bewy]

Voltage readings at the bal resistors sound ok.

 

[Rhino_74Dart]

If it is a true '74 replacement harness, it has the dreaded '74 only seat belt interlock system. It won't fire if the interlock is missing, or the module has tripped and has not been reset. Most people eliminate or bypass the system.

No, it's not a factory replacement. No seatbelt interlock

 

[Johnschummer]

Looks to me like your coil is wired into your wiper bal resistor which should be its own thing. Should be a second bal resistor for just ignition.

 

[Kendog 170]

Not sure on wire colors for your year but my 68 Dart has a blue Ign.1 Run and brown Ign 2 run and start that goes to ballast resistor and not the wiper resistor. Not sure if its a single or dual ballast resistor.

 

[tonysrt]

Because he wired to the wiper resistor, turn on wipers when cranking and maybe it'll fire. There's so much to learn when dealing with cars, especially when torn apart and rewired, but you did the right thing by asking and showing us what you are doing.

 

[Kendog 170]

Does your alt. have 1 or 2 field wires?

 

[Ant]

I know this issue has been beat to death, I've read the posts, watched the videos, and I'm still stumped.

1974 Dart, 318 w/electronic ignition. I drove the car into my garage before tearing it apart, engine was jerry rigged to run stand alone, no ign. switch involved. I just finished rewiring the entire car with AAW kit for A body. It cranks real strong, but will not fire.

Have orange box ICM that was new to get car running. what appears to be factory dist./pickup coil, new coil, new ICM wiring.

I get battery voltage to ballast resistor, both sides, with key on. Don't know if ballast is bad, or because current is not flowing, I have tried 2 different ballasts and both read full voltage on both sides.

I get batt. volt. to + and - sides of coil, and test light only dims while cranking, does not flicker.

ICM box is fully grounded to body, only way to ground more is to weld it.

With ICM harness unplugged, or plugged in, voltage at coil or ballast does not drop. A video said the ICM being plugged in should drop the voltage at coil.

I have quadruple checked connections, and cannot find anything amiss.

I don't have an extra dist., I don't want to remove dist. from engine as it ran to get into garage.

I don't have an extra ICM to swap out, and don't want to throw parts at it. Only part of ignition that isn't new is the dist. and internals.

Wiring is done per AAW, brown wire, Ign. 2 goes to coil +, pink, ign. 1 goes to ballast, along with blue wire from ICM, black ICM wire goes to coil -, green 5th wire is not used, other 2 go to dist.

White tach wire goes to bulkhead, but is not connected, and I have tried disconnecting it, does not help.

Pulled cap, cleaned reluctor and pickup coil contacts, new cap, rotor, plugs and wires.

I don't know how to reliably test dist. pickup, or the ICM to know which part, if any, needs replacing.

View attachment 1716231191

View attachment 1716231192

Oh god! I see the wiring. Rip everything thing out and start over.

 

[Mattax]

just finished rewiring the entire car with AAW kit for A body

Which makes it darn difficult to answer but I can at least point you in the right direction. I see you're ahead of some of the responses. Let
s break it down.

Have orange box ICM that was new to get car running. what appears to be factory dist./pickup coil, new coil, new ICM wiring.

If it worked before then it should work now.
If its newer production (vs. old stock original circa 1974) then only ballast resistor is used. It looks like you chose to mount the resistor on the wiper motor. I'd suggest mounting it where the factory did. It looks like a points type ballast and bracket - approximately 0.6 ohms. Those were mounted under the lip on the firewall, just above the inner fender. Pretty well protected there.

I get battery voltage to ballast resistor, both sides, with key on. Don't know if ballast is bad, or because current is not flowing,

Half correct if you are reading with a meter, or a very very low current test lamp.
With key in run, the power feed is from the ignition run wire only. If there is a reading on the coil/ignition-start side of the ballast resistor then there is continuity.

I have tried 2 different ballasts and both read full voltage on both sides.

see above

I get batt. volt. to + and - sides of coil, and test light only dims while cranking, does not flicker.

Same votlage on both sides of the coil means there is (a) connection to power (b) no current flowing therefore no connection to ground. That means the ECU isn't closing the 'points'.
HOWEVER, this depends on how the test light was connected!
Regardless of how the test light is connected, it will dim when the starter is turning because it draws so much power the battery voltage drops.
Get yourself a cheap multimeter if you dont already have one.

With ICM harness unplugged, or plugged in, voltage at coil or ballast does not drop. A video said the ICM being plugged in should drop the voltage at coil.

That actually is correct. The ECU when powered normally closes the solid state euqivalent to points. Current flows through the ballast from ignition run feed to the coil and then to ground. Each device the current flows through reduces the voltage of the electrons.
During Start, the ignition is powered from the Ignition start feed. Coil + should be close to battery voltage (9.5- 11.5 V while cranking) because current for the coil goes direct (bypasses the resistor) and the ECU connection will be a little less because it has to flow through the resistor.

1. Make sure the battery is charged or the V during cranking may be to low to power the ECU.
2. Make sure the ECU is wired correctly - which I suspect may be the issue. Don't go by colors alone. Go by position of the wires on the ECU connector.

Power for the ECU connects to the top position of the ECU connector.
Coil negative connects to the left of that.
Distributor pickup wires on the right. Those are + and - but if prewired with connector should be OK.

 

[Rhino_74Dart]

Oh god! I see the wiring. Rip everything thing out and start over.

Thanks for your helpful reply, you should send me your address so I can send a thank you gift. WTF is wrong with you? I know it aint pretty, I'm not done yet, wiring is just roughly laid in position, trying to get it running, why be an asshole?

 

[Rhino_74Dart]

Does your alt. have 1 or 2 field wires?

its a Powermaster 1 wire

 

[Rhino_74Dart]

Not sure on wire colors for your year but my 68 Dart has a blue Ign.1 Run and brown Ign 2 run and start that goes to ballast resistor and not the wiper resistor. Not sure if its a single or dual ballast resistor.

View attachment 1716231306

Original 4 post ballast was long gone, I thought previous owner had put in the 2 post ballast, didn't know it was for wiper motor, as my new wiring has direct connections, and doesn't specify anything about a wiper motor ballast. Car only needs a 2 post ballast now. Also, I have changed to a 1 wire Powermaster alt, so no regulator and associated wiring is needed.

 

[Rhino_74Dart]

Looks to me like your coil is wired into your wiper bal resistor which should be its own thing. Should be a second bal resistor for just ignition.

Yea, I didn't know wiper motor had a resistor, the 4 post ballast is long gone, and I thought previous owner had put this 2 post in since the 4 post ballast is no longer needed. But it has run with this setup.

 

[Rhino_74Dart]

If it worked before then it should work now. Yea, it ran with this setup, I drove it into the garage before disassembly, just have replaced all wiring with new harness etc.
If its newer production (vs. old stock original circa 1974) then only ballast resistor is used. It looks like you chose to mount the resistor on the wiper motor. I'd suggest mounting it where the factory did. It looks like a points type ballast and bracket - approximately 0.6 ohms. Those were mounted under the lip on the firewall, just above the inner fender. Pretty well protected there. I didn't know wiper motor had its own resistor, I thought previous owner had eliminated the 4 post ballast and put this 2 post on as the 4 post aren't needed anymore.

Half correct if you are reading with a meter, or a very very low current test lamp. reading voltage with a digital volt meter, using test light on - side of coil while cranking to see if it flickers. (it does not flicker)

1. Make sure the battery is charged or the V during cranking may be to low to power the ECU. brand new battery, fully charged.
2. Make sure the ECU is wired correctly - which I suspect may be the issue. Don't go by colors alone. Go by position of the wires on the ECU connector. I will check again on the ecu/icm wiring, but I'm 99% positive it's correct.

Thank you for such a detailed and polite reply, not everyone on this forum was as kind as you.

 

[Rhino_74Dart]

Wiper motor is NOT wired to the ballast resistor in pics, I did not realize the motor had a ballast resistor, I thought previous owner had installed after removing the 4 post ballast resistor, the wiper motor is fully wired and working, but not to resistor, as the AAW instructions did not specify it needing one. But the car HAS RUN with this ballast resistor.

 

[Mattax]

This is also cheap and handy device

It will show when there is spark while leaving your hands free.


Current and voltage.
Voltage is the level of energy. Current is the amount of electrons moving.
Current can branch off.
Resistance causes current to lose voltage.

Here's a simple diagram of the factory points system begining to start.
Orange arrows represent current flow.

When the starter motor spins, that pulls so much energy the battery voltage drops, but ignition start path remains the same.

Only difference for your set up is the ECU needs to draw power.

 

[Kendog 170]

Did you bypass the ballast to see if it will run just for a test?

 

[Kendog 170]

My wiper motor has a ballast. You can't see my Ignition Ballast but it's behind my air cleaner next to my heater hoses on cowl. Maybe this diagram can help. It is a conversion diagram.

 

[Ant]

Thanks for your helpful reply, you should send me your address so I can send a thank you gift. WTF is wrong with you? I know it aint pretty, I'm not done yet, wiring is just roughly laid in position, trying to get it running, why be an asshole?

View attachment 1716231574

How am I being an asshole? I was just trying to help. I never purposely attacked you or said anything bad about you. So I'm sorry that you are a sensitive Karen and I hurt your feelings.

 

[Mattax]

My wiper motor has a ballast. You can't see my Ignition Ballast but it's behind my air cleaner next to my heater hoses on cowl. Maybe this diagram can help. It is a conversion diagram.

View attachment 1716231899

View attachment 1716231900

Thanks. My bad. Those wiper low speed resistors do look the same, but I think the resistance is much higher than the ignition resistor.

1974 resistors were here. Earlier points ones were under the pinch weld/drip gutter.

That has both the 5 ohm and the 1/2 resistor.
With a replacement ECU, only the 1/2 ohm resistor is needed.

 

[Kendog 170]

That has both the 5 ohm and the 1/2 resistor.
With a replacement ECU, only the 1/2 ohm resistor is needed.

Interesting. I did not know this. Does it have to do with only four pin modules available now?

 

[Mattax]

Does it have to do with only four pin modules available now?

Yes. That is what I was getting at.
If RhinoDart's car has the original ECU, then it needs 5 ohm resistor and all 5 pins connected properly.
If the car has a newer ECU, then that extra power connection can be eliminated and just the 0.5 ohm resistor is needed like your diagram shows.

 

[Mattax]

Here's a '71 with a 0.6 Ohm resistor

One blue wire is from key run. Should have a white tracer on it. The other blue wire goes to the alternator field and voltage regulator.
If converting to ECU, the is a good place to connect the power for it.

With the original '74 wiring, the 5th pin is wired to the additional 5 ohm resistor helps regulate ECU's power.

That's wire J4 in the service manual. J2E is the ECU power wire that connects directly to the ignition run circuit.

So with a newer ECU the 5 ohm resistor and wire J4 can be eliminated. My guess is the wiring kit from AAW didn't even include it.

 

[Mattax]

So the wire from the wiper resistor to the coil is wrong.
That's probbaly a 5 or 8 ohm resistor. I didnt see the spec for the 2 speed wiper in a quick look at the FSM but its probaly in that range.