'66 Valiant Weirdness

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bob_o

bob_o

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My '66 Valiant 225/904 has been having some interesting issues. Apparently I messed up by trying to fix something that wasn't really broke.

I recently got this car back after 10 years of neglect by the PO, so I've been working my way around it making it a dependable driver again. I noticed that the lights were flickering a little bit and after a bit of reading I figured I should go ahead and replace the Voltage Regulator and Alternator, since both appeared to be the original parts. Replacements on RockAuto were very reasonably priced, so I ordered them up (Standard Motor Products PN# VR101T and Pure Energy PN# 7000112). After starting the car the first time with the new parts installed, the needle on the Alternator gauge was jumping around a little bit, but seemed to even out after the car warmed up.

The next day I installed one of these Electronic Distributors and at first everything seemed fine, the car was running excellent with that new ignition system. Then things started getting kinda funky. The Alternator gauge started bouncing around very erratically, even at idle. Didn't seem to matter how much juice I was using as far as the lights, stereo, etc. This first video shows what it was doing while I was sitting parked, engine fully warmed up. You can hear the idle speed changing on its own and the lights getting brighter and dimmer in sync with the gauge.



After that I put the original VR back in, mostly out of curiosity. It was acting like this and added stalling and subsequent hard starting to it's list of misbehaviors.



I'm a decent mechanic, but I'm a **** electrician. Do I need to make an adjustment to the Voltage Regulator? Should I start checking grounds? Hire a witch doctor? Hoping one of you can help me understand and fix this. Any help is appreciated, thanks in advance!
 
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I can't answer your question but I must commend you on your videos and the way you describe the problem. I wish that everyone here could post such descriptive explanations of what they're trying to describe. I'm sure someone will have a good answer for you!!:thumbsup::steering:
 
Show us the regulator. The original one was a mechanical like a relay. Modern replacements should be solid state. IF your new one is solid state, this is likely the age old voltage drop/ "ground loop" problem.

It might be that whatever ignition you installed draws MORE CURRENT, and it is powered off the same circuit as the VR

The circuit path "in general" for the ignition/ VR power for these girls, in general is...........

Battery-----starter relay stud-----fuse link----through the bulkhead connector on ammeter RED wire----to and through the ammeter-----out on the ammeter BLACK wire----to the under dash fuse link----------to the igntiion switch connector---through and back out the switch----back out the switch connector --(on dark blue "ignition run" or IGN1 wire----back out into engine bay through bulkhead connector-----to underhood ignition loads, including VR and ignition system.

THAT CIRCUIT by the way IS NOT FUSED so be some careful

The most common cause of problems is VOLTAGE DROP in this circuit.

1...Turn key to "run" engine off. Check voltage with meter between VR IGN terminal and battery POS terminal. Do not disconnect any wireing, do this with everything connected normally. You are hoping for a very low reading, the lower the better. Anything more than about .3V (3/10 of one volt) you need to look into

2....Ground circuit. VR MUST be at "same as" battery NEG. Start and run car, let battery become "normalized" and with engine running on fast idle, do this test first with everything "off" and again with heater lights, etc powered on

Stab voltmeter probe into mounting flange of VR and remaining probe into top of battery NEG post. As before, you are hoping for a very low reading, zero is perfect. Any voltage a tenth or two, improve the grounding between battery and body/ VR case

VR MUST be scraped clean and firewall, mount with star lock washers.
 
CURRENT through a circuit causes voltage drop. What might be happening, is that the new ignition draws more or less current at different RPM. As far as the flickering, a bad connection can "break" and drop connection so to say, then current starts to drop and connection sort of arcs across and remakes. There are other reasons, but there can be what are sometimes called "loops" or "ground loops." These can cause certain interesting cycling.
 
67Dart273 said:
Show us the regulator. The original one was a mechanical like a relay. Modern replacements should be solid state. IF your new one is solid state, this is likely the age old voltage drop/ "ground loop" problem.

It might be that whatever ignition you installed draws MORE CURRENT, and it is powered off the same circuit as the VR

The circuit path "in general" for the ignition/ VR power for these girls, in general is...........

Battery-----starter relay stud-----fuse link----through the bulkhead connector on ammeter RED wire----to and through the ammeter-----out on the ammeter BLACK wire----to the under dash fuse link----------to the igntiion switch connector---through and back out the switch----back out the switch connector --(on dark blue "ignition run" or IGN1 wire----back out into engine bay through bulkhead connector-----to underhood ignition loads, including VR and ignition system.

THAT CIRCUIT by the way IS NOT FUSED so be some careful

The most common cause of problems is VOLTAGE DROP in this circuit.

1...Turn key to "run" engine off. Check voltage with meter between VR IGN terminal and battery POS terminal. Do not disconnect any wireing, do this with everything connected normally. You are hoping for a very low reading, the lower the better. Anything more than about .3V (3/10 of one volt) you need to look into

2....Ground circuit. VR MUST be at "same as" battery NEG. Start and run car, let battery become "normalized" and with engine running on fast idle, do this test first with everything "off" and again with heater lights, etc powered on

Stab voltmeter probe into mounting flange of VR and remaining probe into top of battery NEG post. As before, you are hoping for a very low reading, zero is perfect. Any voltage a tenth or two, improve the grounding between battery and body/ VR case

VR MUST be scraped clean and firewall, mount with star lock washers.
Click to expand...


Hey 67Dart273,

Just looking at the ammeter movement erratically moving. If there was too little current moving through it, would the reading just drop and not move around like this? I wouldn't expect an electronic regulator to perform like this .Mechanical regulator with points, contacts etc.. yes.
I would think that the ammeter moving around like this caused by sparking , very poor ground or poor connections as current flow is being interrupted.

Interested in your thoughts on this .

Cheers!!
 
I don't think of these systems in that way There are several "areas" and ways that I look at this:

1...Battery must be in good shape, not sulfated, or worn out, or with bad cells. "A normal battery."

2...Generally connections and cables must be good, clean, tight.

3...Charging path. The output path from the alternator stud, through the bulkead, ammeter, back out bulhead, to battery. If there are bad connections here, can cause unacceptable voltage drop as well as this kind of nonsense.

4...Field circuit. This is the entire circuit from battery, ammeter, ignition switch, VR IGN terminal, (VR ground), to green alternator field connection, and condition of brushes, slip rings.

5....Components, VR and alternator

AFTER checking the wiring and battery in 1--4 above, then worry about if VR or alternator has a problem. It is possible for field windings, example to rub on each other, become loose, and short together. This will cause ammeter fluctuations, as well as an interesting lightning show in the dark, inside the alternator.

Bad/ worn brushes and slip rings can cause weird problems

And "once in awhile" a bad VR particularly an older MECHANICAL VR can cause flickering.

That generally is how I go about it. Attack the wiring and connections. Then check the alternator, and VR

And, as usual, "new" does not mean "good." New components can be defective, and rebuilds are always suspect
 
67Dart273 said:
I don't think of these systems in that way There are several "areas" and ways that I look at this:

1...Battery must be in good shape, not sulfated, or worn out, or with bad cells. "A normal battery."

2...Generally connections and cables must be good, clean, tight.

3...Charging path. The output path from the alternator stud, through the bulkead, ammeter, back out bulhead, to battery. If there are bad connections here, can cause unacceptable voltage drop as well as this kind of nonsense.

4...Field circuit. This is the entire circuit from battery, ammeter, ignition switch, VR IGN terminal, (VR ground), to green alternator field connection, and condition of brushes, slip rings.

5....Components, VR and alternator

AFTER checking the wiring and battery in 1--4 above, then worry about if VR or alternator has a problem. It is possible for field windings, example to rub on each other, become loose, and short together. This will cause ammeter fluctuations, as well as an interesting lightning show in the dark, inside the alternator.

Bad/ worn brushes and slip rings can cause weird problems

And "once in awhile" a bad VR particularly an older MECHANICAL VR can cause flickering.

That generally is how I go about it. Attack the wiring and connections. Then check the alternator, and VR

And, as usual, "new" does not mean "good." New components can be defective, and rebuilds are always suspect
Click to expand...


Thanks for the detailed reply 67 Dart 273 .

Boy do I know about this one!!

"And, as usual, "new" does not mean "good." New components can be defective, and rebuilds are always suspect..."
 
Treblig said:
I can't answer your question but I must commend you on your videos and the way you describe the problem. I wish that everyone here could post such descriptive explanations of what they're trying to describe. I'm sure someone will have a good answer for you!!:thumbsup::steering:
Click to expand...

I appreciate that! Part of my job requires a bit of Technical Writing and it really comes in handy for stuff like this!
 
Thanks for the thorough responses, gents. I won't have the time to really dig into these suggestions until this weekend, but in the meantime, here's pics of the OE VR and the replacement one I bought. The one that was in the car is on the left, newbie on the right.

IRocKKh.jpg

8pRD2hC.jpg

BmlRInw.jpg


Out of curiosity, what is the point gap supposed to be on these Voltage Regulators?
 
Point gap is in the factory service manual.
if you don't have one, you may be able to download one in pdf from mymopar.com Dodge or Plymouth for the same year will be very similar.
I like a print copy too and have always bought one for the specific year I actually own.

As far as the ammeter bouncing that quick, I would suspect connections as much as suspecting the VR.
When the VR's points connect together power flows direct to through rotor's windings. That creates a spinning magnetic field. That in turn induces the electrons in the fixed windings (stator) to try to move. When the points change position, less current or no current flows through the rotor. The magnetic field starts to decay. It doesn't flip on and off - and that's the reason I don't think its the VR.

This Chrysler booklet explains that in more detail.
Alternators and Regulators (Session 228) from the Master Technician's Service Conference

The MTSC Series is a very useful resource. Here's the index at Imperal Club
Master Technician Service Conference - Chrysler's Training for Mechanics

Mymopar has most of these in pdf format if you prefer that.
 
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bob_o said:
Do I need to make an adjustment to the Voltage Regulator?
Click to expand...
Probably not but since its off now might as well do the easy checks.
bob_o said:
Should I start checking grounds?
Click to expand...
Yes.
And then the power feed and charge connections.
Here's the thing to understand.
There are two power sources, right?
But the one can only supply power at 12.8 Volts in the best of situations.
The other can supply power at 14 volts give or take a little.
So between the two possibilites, electricity always flows from the higher voltage source, as long as it has enough power and the resistance is about equal.

The ammeter is in line with the battery.
It only shows if the alternator is recharging the battery or if the battery is discharging.
This would be the current flow of a normal recharge after starting.

basic-charge-circuit-charging-animated-gif-gif-gif.gif


After the battery gets recharged, the flow through that line is essentially zero.
upload_2019-9-27_20-48-1-png-png.png


But if there is a loose connection on the alternator output line, then the battery will fill in and the ammeter will show discharge.
I thought I saw that a couple times in one of your vids, but I might be mistaken.
 
Forgot to mention that when there is weirdness in the ammeter readings one of the first things I do after a quick visual check of the wiring is check voltage.

With engine running measure voltage at battery positive, alternator output and at or near the regulator input (aka ignition wire connection at the ballast or the regulator).
Knowing the voltage at these locations plus what the ammeter is showing for current to/from the battery helps make a complete picture.
I also check it engine off just to get a ballpark on the battery condition.
 
Not sure if this was asked and answered but I had a similar weird charging system with my 66 Valiant. I had replaced the alt and VR and things got very wacky.
Turns out I had gotten a "newer" square back alternator and it had dual "fields". I had connected one and left the other not used. I needed to ground the one that was not used.
Just my $0.02.
Good luck!
 
During the course of my investigations utilizing info you guys have so kindly offered up, I discovered that the source of the stalling problem was the carb. Considering I rebuilt it 10 years ago and it is the only carb rebuild I've ever done before or since, it's practically a miracle it lasted this long.

So without being able to keep the car running long enough to properly diagnose the charging issue, I decided to go ahead and begin installing the 2bbl setup I've put together. Also, my solid state VR showed up today, so once the carb/intake/exhaust swap is complete, I can jump back on the charging system checks.
 
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