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The big Wilcox diagram in post 190 clearly shows this mystery ground wire, "near" the starter, and heading straight back to the blower motor., 14 gauge, black.
It could be shorted to a power wire somewhere along it's length. Or on the wrong screw somewhere.
You need to start tracing all those starter and coil wires.
The issue is in there somewhere.
The big Wilcox diagram in post 190 clearly shows this mystery ground wire, "near" the starter, and heading straight back to the blower motor., 14 gauge, black.
It could be shorted to a power wire somewhere along it's length. Or on the wrong screw somewhere.
You need to start tracing all those starter and coil wires.
The issue is in there somewhere.
Thanks to everyone’s input this is narrowed down to a key area. The mystery is how the car ran very well at times but missing at others. I’m thinking a rubbing or intermittent touching wire. If it was a miss attached wire it should be consistent?
Maybe a grounding wire at alternator or some other point not correct?
KC
A bit of hiatus due to life! It’s been so long I had review what I’ve even done. I opened up some of the wiring harness form the firewall on down to the starter. The (R) run wire from the starter looked frayed and possibly breached the insulation so I replaced that wire. Quick test drive let me know that wasn’t the issue.
I re checked the coil voltage with the ignition on and car not running, it was 6.83 volts.
I checked the voltage with the car running and the voltage was 13.0 volts at the positive coil terminal.
It’s my understanding that this is incorrect voltage with the car running.
I have looked at the power wire for possible rubbing into another wire but haven’t discovered a break yet.
Im not sure what to test next, hhmmm.
KC
Last edited by grumman41; Jun 17, 2025 at 08:46 AM.
A well-functioning alternator should be right around 14.2v (13.8-14.5) between the battery terminals while idling. See if you get the same 13v at the battery. If so, I'd say your alternator isn't putting out the juice -- if all of your connections are clean and snug.
A well-functioning alternator should be right around 14.2v (13.8-14.5) between the battery terminals while idling. See if you get the same 13v at the battery. If so, I'd say your alternator isn't putting out the juice -- if all of your connections are clean and snug.
Barkingrats, can you clarify a bit? You said the alternator should be around 14.2, where is that measured at? I’m a bit confused with the post above as it sounds like both measurements are at the battery?
Barkingrats, can you clarify a bit? You said the alternator should be around 14.2, where is that measured at? I’m a bit confused with the post above as it sounds like both measurements are at the battery?
Yes, I'm suggesting getting readings off the battery with the engine idling. You should see ~14.2v but I'm wondering if your 13v coil measurement is showing the same at the battery.
Yes, I'm suggesting getting readings off the battery with the engine idling. You should see ~14.2v but I'm wondering if your 13v coil measurement is showing the same at the battery.
The car has been sitting but measured 11.88 volts with the car off and 14.0 once started. The alternator is working, the battery was at 13.70 and rose to 14.0 in a few minutes.
Did you ever try running the car with the bypass wire removed to eliminate the starter side of the coil power ? That way you can eliminate that side of the fugitive power .
Did you ever try running the car with the bypass wire removed to eliminate the starter side of the coil power ? That way you can eliminate that side of the fugitive power .
Smilie, would that be the (R) wire from starter solenoid to plus side of coil? If so, I did. The car started and died about one second later.
It should have stayed running without that wire connected . That wire only supplies power when the starter is engaged . Sometimes they're hard to start without that wire but will usually start . I would suspect that is the only wire supplying coil power .
It should have stayed running without that wire connected . That wire only supplies power when the starter is engaged . Sometimes they're hard to start without that wire but will usually start . I would suspect that is the only wire supplying coil power .
Smilie, can you clarify which wire you are talking about at the coil? I have three wires on the plus side of the coil. The resistance wire from the firewall, the (R) wire from the starter and the resistor.
Update:
With the ignition in the on position the Black wire (marked resistance) measures 11.35 volts.
The wire from the starter (R) is measuring 13.5 volts with the ignition in the off or on position.
Last edited by grumman41; Jun 18, 2025 at 10:21 AM.
I can not imagine what would cause a "R" wire from the starter to keep supplying 13V, long after start-up, except a problem with the relay / solenoid in the starter itself. The 12v supplied from that wire should go to zero once the starter is not running.
Agree with above, even if you disconnect that R wire, it should start and run. It may be harder to start, but should run just fine. And have less than 12V when running. (~9v?)
As far as I remember there should only be 2 wires feeding the coil + . The wire from the starter and the wire from the ignition switch . Have you tried not connecting one of the other two wires ( the one you call the resistance wire from the firewall or the one you call from the resistor ) ? I would think you only need one .
As far as I remember there should only be 2 wires feeding the coil + . The wire from the starter and the wire from the ignition switch . Have you tried not connecting one of the other two wires ( the one you call the resistance wire from the firewall or the one you call from the resistor ) ? I would think you only need one .
I unhooked the (R) wire from the starter, the car did start and the plus side of the coil read 14.0 volts with the engine running. It read 12volts with the ignition in the on position and engine not running.
But it also sounds like that 14v wire is no longer a resistor wire. Sounds like someone swapped in a regular wire, likely for a non points ignition system.
Now will that hurt the car and make it run bad?
Yes, a full 12 V, non-stop, will burn the points. And then they will have high resistance and the car will act up.
Now the wire that goes to the starter, that you disconnected, make sure it has zero volts with the key in the run position. You do not even have to start the engine..
It should only have juice when the key is in "START".
But it also sounds like that 14v wire is no longer a resistor wire. Sounds like someone swapped in a regular wire, likely for a non points ignition system.
Now will that hurt the car and make it run bad?
Yes, a full 12 V, non-stop, will burn the points. And then they will have high resistance and the car will act up.
Now the wire that goes to the starter, that you disconnected, make sure it has zero volts with the key in the run position. You do not even have to start the engine..
It should only have juice when the key is in "START".
It sounds like with everyone’s help that this is getting narrowed down to incorrect wiring or voltage to the coil which is messing up points.
Just wanted to clarify to make sure we are all on the same page, I’m familiar with the distributor condenser, what it does and how it’s wired to the the plus coil.
I refer to the black firewall power wire to the plus side of the coil as the resistance wire as it says resistance wire on it. I’ll test a few things recommended this evening and report back.
Leigh, I did check the wire from the starter (R) and it does have 12.0 volts with the ignition in the on position and the engine not running. It’s my understanding (maybe from you) that this wire should only have power momentarily during the start phase.
KC
Last edited by grumman41; Jun 19, 2025 at 10:44 AM.
Quote below:
The "R" terminal on a starter solenoid plays a specific role in some older vehicle ignition systems, particularly those with a points-type ignition and ballast resistor. Here's how the R terminal works:
Bypassing the Ballast Resistor: When the starter is cranking, the R terminal on the starter solenoid is energized, essentially acting as a relay. This energized terminal bypasses the ignition coil's ballast resistor, providing full battery voltage (around 12 volts) to the ignition coil.
Providing a Hotter Spark: Engines with a points-type ignition and ballast resistor require about 9.5 volts to run properly. However, during cranking, the battery voltage drops due to the high current draw of the starter motor. Providing 12 volts via the R terminal during this time ensures a hotter spark, which helps the engine start more easily.
Deactivating After Starting: Once the engine starts and the starter motor is deactivated, the R terminal loses power, and the ignition coil is then supplied voltage through the ballast resistor as usual. This helps to protect the ignition points from excessive current.
In summary: The R terminal acts as a temporary power source for the ignition coil during engine cranking, ensuring adequate voltage for starting, especially in older ignition systems with ballast resistors.
Quote below:
The "R" terminal on a starter solenoid plays a specific role in some older vehicle ignition systems, particularly those with a points-type ignition and ballast resistor. Here's how the R terminal works:
Bypassing the Ballast Resistor: When the starter is cranking, the R terminal on the starter solenoid is energized, essentially acting as a relay. This energized terminal bypasses the ignition coil's ballast resistor, providing full battery voltage (around 12 volts) to the ignition coil.
Providing a Hotter Spark: Engines with a points-type ignition and ballast resistor require about 9.5 volts to run properly. However, during cranking, the battery voltage drops due to the high current draw of the starter motor. Providing 12 volts via the R terminal during this time ensures a hotter spark, which helps the engine start more easily.
Deactivating After Starting: Once the engine starts and the starter motor is deactivated, the R terminal loses power, and the ignition coil is then supplied voltage through the ballast resistor as usual. This helps to protect the ignition points from excessive current.
In summary: The R terminal acts as a temporary power source for the ignition coil during engine cranking, ensuring adequate voltage for starting, especially in older ignition systems with ballast resistors.
Thanks Leigh! This all makes sense now. I’ve just got to figure out if some wires has been changed, connected incorrect or possibly “feeding” into another wire. I think it’s something obvious I’m overlooking. If not too tired after work I should be able to sort this out and report back. The driving season is here so pressure is on get this sorted.
KC
