Recently put on all new exhuast, I think I might have knocked a wire off or loosened one. Now won't start until key is returned to run position. Any ideas where to start looking? Thanks in advance.
Ignition problem
- Thread starter andysauto1
- Start date
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Tanker
My first Chrysler
Are you saying that it will crank endlessly until you back the key off to the run position, and then it finally starts?
yes, exactly
Tanker
My first Chrysler
My 318 did this for several months before it died completely. A timing light showed the timing mark jumping around which left my dad scratching his head wondering what would cause that. The answer wasn’t long in coming. My engine had nylon teeth molded onto the timing gear. Either the teeth had worn down or the chain had stretched over time. I don’t know which was the case. Either way, the timing chain had developed enough slack that when the starter was engaged the slack was pulled out of one side and added entirely to the other. This caused a misalignment of the crank and cam. The moment I released the starter things fell back into alignment and it fired. I drove the car this way for a few months wondering what was going on, then the timing chain jumped a few teeth, the pistons came up and whacked all the valves, and that was that. My car spent the next thirty years sitting at the end of my parent’s driveway. Put a timing light on your engine and make sure you aren’t having the same problem.
Thanks, I will get a light on it this week
Daves69
Well-Known Member
Probably should provide more info.
Vehicle year & make
type of ignition
This kind'a sounds like an open circuit in the "start" mode to me.
Maybe check for loose / dirty bulkhead and ballast connections.
72 340 4 speed demon
Factory electronic ignition
remytherat
Well-Known Member
Sounds like the ignition 2 circuit is not working. To rule that out, you could try hotwiring it and see if it starts normally, In that case, you would know that the coil isn’t getting voltage while cranking.
I think you are on to something there, makes sense to me, thanks
That means that one of your ignition switch circuits is not powering your coil. There are two power sources for power from the ignition switch.
One supplies power during cranking, which bypasses the ballast resistor. It is called Ignition 2, Brown wire
One supplies power in the run position, which goes through the ballast resistor. It is called Ingition 1, Dark Blue wire.
So this means your car is likely supplying power on the blue wire, but not the brown wire.
Look for broken wires near your ballast resistor as a start.
Could also be bad ignition switch.
These colors are for 1969, I think they are the same for other years.
One supplies power during cranking, which bypasses the ballast resistor. It is called Ignition 2, Brown wire
One supplies power in the run position, which goes through the ballast resistor. It is called Ingition 1, Dark Blue wire.
So this means your car is likely supplying power on the blue wire, but not the brown wire.
Look for broken wires near your ballast resistor as a start.
Could also be bad ignition switch.
These colors are for 1969, I think they are the same for other years.
With factory electronic ignition the ignition start circuit has two jobs:
1. Feed the coil.
2. Feed the ECU.
IIRC '72 may have an additional engine bay connector for ignition start to run through. Its possible it got yanked or a cross wire short if pinched during the exhaust work. In the service manual ignition start (Ignition 2) wires are labled J3. From the ignition switch to the ballast resistor junction, they are usually brown.
1. Feed the coil.
2. Feed the ECU.
IIRC '72 may have an additional engine bay connector for ignition start to run through. Its possible it got yanked or a cross wire short if pinched during the exhaust work. In the service manual ignition start (Ignition 2) wires are labled J3. From the ignition switch to the ballast resistor junction, they are usually brown.
Why ?
remytherat
Well-Known Member
Lol because this is an old car forum, someone’s gotta say it
mopar head
Well-Known Member
A quick continuity test on the ballast resistor should let you know if it`s good or not.
Inertia
Well-Known Member
I want to say cuz the resistor by-pass isn't working, but then realize my international traits are showing. lol
I'm trying to remember why we always carried a spare resistor in the glove box, I'm just too old.
Please refresh my memory, thanks .
remytherat
Well-Known Member
Usually a bad ballast causes the opposite issue, starts while cranking then dies in run position. It theoretically could cause his problem too, just an unlikely culprit, especially since we know old wires were getting messed with.
If you have a multimeter, you can check the connections through to the ballast resistor junction of the ignition start.
With the battery disconnected, use ohms or continiuity.
With the battery connected, use Volts DC.
I think in this case I'd prefer to measure volts.
Clip the hot lead to the junction on the ballast or coil. Doesn't matter in this case because start bypass the ballast resistor.
Here's diagram showing the connections on a points equiped '72. We'll get to ECU version next.
With the key on start, battery power should be available at the J3 to J2B junction. A volt reading there should jump to battery voltage and the ammeter should swing slightly toward discharge. When the starter engages, battery voltage will drop. It should be no lower than 9.5 Volts. if its lower than that, then measure the voltage at the battery during start to see if there is resistance in the circuit feeding wire J3.
Lots of great info,thanks to everyone
Remy's got it.
With the factory ECU, the ballast does have a role during start, but since the ignition works with the key in run, its not likely to be the issue.
So here's how the factory diagram shows the ECU wiring was incorporated.
You'll have to tell us whether the insulation color of the wire connecting to the coil positive was changed to brown at this time. it was in '73 but '72 I'm not sure.
Notice the starter switch has two seperate connections for starting. One to the starter relay and one for the ignition.
Even what I've drawn is not quite true. The terminals are not connected together inside the switch, except when the key is held in start.
The point is there can be a good connection to the starter relay and a poor connection to the ignition circuit.
With the factory ECU, the ballast does have a role during start, but since the ignition works with the key in run, its not likely to be the issue.
So here's how the factory diagram shows the ECU wiring was incorporated.
You'll have to tell us whether the insulation color of the wire connecting to the coil positive was changed to brown at this time. it was in '73 but '72 I'm not sure.
Notice the starter switch has two seperate connections for starting. One to the starter relay and one for the ignition.
Even what I've drawn is not quite true. The terminals are not connected together inside the switch, except when the key is held in start.
The point is there can be a good connection to the starter relay and a poor connection to the ignition circuit.
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If the engine runs in the run position the ballast is fine
What the op has described is a typical no power to the bypass (IGN 2) during cranking.
It can happen in a few ways.
What the op has described is a typical no power to the bypass (IGN 2) during cranking.
It can happen in a few ways.
- The wire from IGN 2 has come off or has been cut from the coil side of the ballast during header install.
- The ignition switch has failed (coincidentally to the header install)
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Inertia
Well-Known Member
Yep, my memory definitely failed me there, shoulda thought it thru .
Thank-you
easy when we're not using that bit of information for a while.
happens to all of us.
just that not all admit it!
Update, yes it was run 2 wire which is a brown wire on my car. Wire was old and brittle, wiggled it and started like normal so I replaced it with new. Got to looking and there is several wires I may want to replace. I don't know much about the car, I bought it , loaded it on the trailer then off and into my shop at home. Had it a year and a half prepping body and rebuilding front end on it. Any way thanks for everybody's help, just one less headache for me.
Glad you found it. That's not a wire that I've seen get cooked a lot but I haven't worked on a 70s car in a long time. Steering column connector, and the later cars (73?) with engine connectors are often trouble spots. Also connections in the bulkhead multi-connectors - epsecially high load ones.
A lot of times the wires get knocked about and removed from the cable wrap etc etc. They then had to survive us who derided all those wire clips and hangers as a pain in the ***. Little did we know there was a reason for them....
Watch out for some of the connectors and replacement terminals. Most, but not all, will be a Chrysler/Ford terminal thats like a Packard 58. When used with Packard 56 they don't always fit right resulting in a loose terminal when the connector is installed. Just a slight difference in length but prevents a good contact.
edit: jsut remembered these
This photo I took at carlisle 2019 is of a claimed '72 survivor. The earlier cars had the ballast protected by the drip edge.
I'm sure it can get quite hot in here plus oil fumes etc
A lot of times the wires get knocked about and removed from the cable wrap etc etc. They then had to survive us who derided all those wire clips and hangers as a pain in the ***. Little did we know there was a reason for them....
Watch out for some of the connectors and replacement terminals. Most, but not all, will be a Chrysler/Ford terminal thats like a Packard 58. When used with Packard 56 they don't always fit right resulting in a loose terminal when the connector is installed. Just a slight difference in length but prevents a good contact.
edit: jsut remembered these
This photo I took at carlisle 2019 is of a claimed '72 survivor. The earlier cars had the ballast protected by the drip edge.
I'm sure it can get quite hot in here plus oil fumes etc
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