Flicker flutter

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Glenn’s HC

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Folks , 68 Barracuda , has been upgraded some years back to typical mopar electronic ignition, recently new alternator ballast and voltage regulator. I haven’t had the car too long and never got the chance to drive it at night until after some of the parts changes . However , the lights flicker with acceleration, more pedal , faster flickering , all lights not just head lights . At idle it’s ok . The flickering are in sync with engine revolutions. All grounds are clean and good. No faulty or crusty connections Any where that I can tell . Ignition coil is stock, ignition wires are 8mm performance wires. No radio noises or interference detected.

Any ideas ??
 
Easiest thing to do is have your charging system checked at an autoparts store. Their testers can detect bad diodes etc.

Another quick test is to remove field wire / wires and text again.

If the issue is still there the problem is in the ignition system somewhere.

If it is not there then the problem is in the charging system.
 
ideas sure, but better to figure it out

What did the ammeter show when this was happening?
That will provide clues as to where to start looking.

The ammeter goes from 40 amps discharge to 40 amps charge. The meter indicates current flowing in or out of the battery. For whatever reason, its labelled 'Alternator'. However if you see the ammeter showing discharge, when the engine is running, then the alternator is not providing enough power to cover the system needs.

The ammeter should show charging after start, then go to zero.
Sometimes it may show very slight discharge with lights and heater on at slow idle.
Then at higher engine speeds it will charge back up. Once the battery is charged, the needle again should be centered.
 
Most likely cause is (no particular order) a "loop" situation which is reality could actually be a somewhat poor connection, either in ground or hot side of harness

Poor regulator. If you have a mechanical regulator, replace it

If it's a very "fast" flicker it could be something like a poor connection in the charge path.

Bad/ poor condition slip rings or brushes but they are usually unpredictable
 
I had flickering while idling. Went with Promaster 1-wire alt (got rid of voltage reg) and crackedback wiring harness who also had the wire for alternator. Works great now.
 
ideas sure, but better to figure it out

What did the ammeter show when this was happening?
That will provide clues as to where to start looking.

The ammeter goes from 40 amps discharge to 40 amps charge. The meter indicates current flowing in or out of the battery. For whatever reason, its labelled 'Alternator'. However if you see the ammeter showing discharge, when the engine is running, then the alternator is not providing enough power to cover the system needs.

The ammeter should show charging after start, then go to zero.
Sometimes it may show very slight discharge with lights and heater on at slow idle.
Then at higher engine speeds it will charge back up. Once the battery is charged, the needle again should be centered.
Amp gauge is always above center for the most part
 
Most likely cause is (no particular order) a "loop" situation which is reality could actually be a somewhat poor connection, either in ground or hot side of harness

Poor regulator. If you have a mechanical regulator, replace it

If it's a very "fast" flicker it could be something like a poor connection in the charge path.

Bad/ poor condition slip rings or brushes but they are usually unpredictable
Though the regulator is new old style , I have a solid state regulator new in stock , I’m going to give that a try .
 
Could just need a cleaning of the points. Considering the quality of replacement parts....
Yea “quality “ hummm yea , Pretty much even a known
brands such “standard “ automotive parts come from China in Mexico I have a standard brand brand new voltage regulator in there now. I know it’s new and it doesn’t mean anything or because it’s new but it is performing the job of keeping the voltage at proper rates however I have a brand new regulator for a 73 to 75 which is solid state I’m going to try that next and see if it cleans up the signal
 
Amp gauge is always above center for the most part
To use the ammeter, and actually also a voltmeter, for troubleshooting the observations need to made in conjunction with the situation. Change the situation and new readings need to be made. Both sets readings are valid and useful knowing what was going on at the time of each.

Not really sure what above center is, or what situation was happening at the time.
Do this for your own basedline.
if you want to get fancy, do it with a voltmeter where you can see it (cowl?) and clipped to read across the battery to ground.
1. Open the door/turn the interior lights on. The ammeter should show 2-4 amps discharge. The voltmeter probably won't show much change.
2. Turn on the headlights, note the gages shows.
3. Turn all the lights off, start the car. The meter should go slight discharge, then to charge. Is the needle bouncing? It shouldn't be, Is the engine on fast idle, if so note that. Let it charge for a few minutes. The need should go to zero.
4a. While running with the battery now charged, turn on the headlights. What's ammeter show? What's voltmeter doing.
4b. If its on slow idle, increase the rpm, Observe the readings as the rpm increases. Get it upto 1500 or 2000 rpm, nothing higher really needed.
 
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I have a standard brand brand new voltage regulator in there now. I know it’s new and it doesn’t mean anything or because it’s new but it is performing the job of keeping the voltage at proper rates however I have a brand new regulator for a 73 to 75 which is solid state I’m going to try that next and see if it cleans up the signal
Before swapping more parts.
With voltmeter attached to the alternator output stud and a ground, increase the rpm from slow idle to 1500 or 2000 rpm.

When I wrote clean the points, I was referring to a mechanical type regulator. 67Dart273 pointed out that mechanical regulator can cause some fluttering. My point was only that those can often be cleaned up. Just remove the cover and see what the condition is. If there is a new regulator on the car now it could be mechanical, or it could be transistorized inside.

As far as a regulator for 73-75, that doesn't sound right. The vast majority of these cars use a feed controlling regulator up through 1969 models. One connection to the power source, and aanother connection that is internally controlled connection feeding the alternator's rotor.
From 1970 to the end of the line, the vast majority of these cars used a regulator that controlled the ground connection. These regulators have a triangular plug connector with 2 terminals. One terminal senses voltage, the other connects to the alternator's rotor and controls connection to ground. This regulator can not be used with the earlier alternator.
Photos and more in Identifying Chrysler Alternators (1960-1976)
 
Just rereading what you first posted to see what I may have missed or misread.
recently new alternator ballast
The ballast resistor is for the ignition. It lowers the voltage so the coil doesn't draw too much and also helps protect the distributor's points. For a points system it should be somehting like a 0.7 Ohm resistor and for a Chrysler electronic system it should be 0.5 Ohms.

There is connection to the voltage regulator at one of the ballast resistor terminals. That was just a convenient location for the factory to make a junction. The alternator and regulator do not use the ballast resistor.
upload_2022-1-1_21-0-29.png


The flickering are in sync with engine revolutions.
Not sure but this is why I suggested observing alternator output voltage with rpm.
The ammeter will only indirectly a voltage regulation problem.
 
Amp gauge is always above center for the most part
This right here might be a clue. Often the regulator is not at fault but if it's a mechanical type it could be. But VOLTAGE DROP in the harness or ground WILL cause overvoltage, and bad connections in the harness will. This is a VERY common problem. Try disconnecting the IGN terminal of the VR, and connecting a temporary jumper from there direct to the batter and see if things "settle down," both the flicker and the over--voltage. With battery "up and normal" and the engine warm, and running at high idle, measure battery voltage. Should run about 13.5--14.2V

MAKE CERTAIN, absolutely certain, that the VR is grounded, and that the battery has a good ground path to the body

I like to add a BIG ground jumper. Look at the holes in the end of the pass. side head. Those same holes are unused on the firewall end of the driver's head. Add a short "starter" cable (eyelet to eyelet) about a foot long from a short bolt into the head, to the firewall. The mounting studs for the master cylinder are good.
 
Just rereading what you first posted to see what I may have missed or misread.

The ballast resistor is for the ignition. It lowers the voltage so the coil doesn't draw too much and also helps protect the distributor's points. For a points system it should be somehting like a 0.7 Ohm resistor and for a Chrysler electronic system it should be 0.5 Ohms.

There is connection to the voltage regulator at one of the ballast resistor terminals. That was just a convenient location for the factory to make a junction. The alternator and regulator do not use the ballast resistor.
View attachment 1715846081


Not sure but this is why I suggested observing alternator output voltage with rpm.
The ammeter will only indirectly a voltage regulation problem.
Thank you for all the time and effort you’re putting into this please know I am fully aware of all the components of the car and what they do and wiring issues are not a problem for me I am an HVAC controls tech I am very trained on circuits connections plugs resistance wiring well things of that nature I mention what I changed in the car as a reference because most people when you post will ask you what you’ve recently changed or not so after I purchased the car it did need an alternator and for good measure I put in a new standard automotive regulator. When I mentioned the new voltage regulator for 73 to 75 I may have made a mistake I have also purchased a solid state blue in color replacement voltage regulator which I have not tried yet. Since the fluttering is in tune with the engine almost as if every revolution causes a flutter on time with with the exhaust note of the engine I was thinking of some sort of interference from the ignition circuit to which naturally the ballast resistor is part of I did not mean to imply or point to any direction of problem to the ballast resistor only mentioned that it was changed along with a couple of the parts that needed to be changed at the time.
 
This right here might be a clue. Often the regulator is not at fault but if it's a mechanical type it could be. But VOLTAGE DROP in the harness or ground WILL cause overvoltage, and bad connections in the harness will. This is a VERY common problem. Try disconnecting the IGN terminal of the VR, and connecting a temporary jumper from there direct to the batter and see if things "settle down," both the flicker and the over--voltage. With battery "up and normal" and the engine warm, and running at high idle, measure battery voltage. Should run about 13.5--14.2V

MAKE CERTAIN, absolutely certain, that the VR is grounded, and that the battery has a good ground path to the body

I like to add a BIG ground jumper. Look at the holes in the end of the pass. side head. Those same holes are unused on the firewall end of the driver's head. Add a short "starter" cable (eyelet to eyelet) about a foot long from a short bolt into the head, to the firewall. The mounting studs for the master cylinder are good.

yes although it’s new the Regulator is a mechanical replacement , I’m going to try a solid state replacement that may work better with the rebuilt alternator Which may have been overhauled with more solid state components like 73-76 alternators are. All other tests I’ve done are normal. Grounds are all good , wiring is good , bulkhead and connections are good .
 
Most 60-69 mechanical regulators are actually solid state replacements. I don't know where you would even buy an actual mechanical other than "new old" stock. Look on the bottom. If there are two large wire wound resistors, it is mechanical. If nothing there it's electronic replacement.
 
If connections ok, I would try another battery if you have, even if you just hook up with jumper leads. The battery acts a 'large electrical anchor', for want of a better term; it smooths out the pulsating DC waveform of the alt output. If the battery has high resistance internally [ or in the main connections ], it may not be smoothing out the pulses, which you see as flickering lights.
 
If connections ok, I would try another battery if you have, even if you just hook up with jumper leads. The battery acts a 'large electrical anchor', for want of a better term; it smooths out the pulsating DC waveform of the alt output. If the battery has high resistance internally [ or in the main connections ], it may not be smoothing out the pulses, which you see as flickering lights.

although the battery is brand new , I’ll pop in another one just to try. You hit On something that I’ve also thought , “ smoothing out the pulses” it’s funny how it pulses , as if it’s in tune with the engine , if we said , ding ding ding ding ding ding, (as if it was the engine at idle) at the beginning of every “ding” , the lights flicker. Not so much at idle but from 1500 rpms and beyond.
 
Folks , 68 Barracuda , has been upgraded some years back to typical mopar electronic ignition, recently new alternator ballast and voltage regulator. I haven’t had the car too long and never got the chance to drive it at night until after some of the parts changes .


However , the lights flicker with acceleration, more pedal , faster flickering , all lights not just head lights . At idle it’s ok .

What does your Ammeter show, discharge or charge, under these conditions?
If it is in discharge at idle and no flicker I would suspect the alternator.


The flickering are in sync with engine revolutions. All grounds are clean and good. No faulty or crusty connections Any where that I can tell . Ignition coil is stock, ignition wires are 8mm performance wires. No radio noises or interference detected

This makes me feel like there is a LARGE draw during the revolutions of the engine, or the output from the alternator is not being rectified correctly.

As asked earlier what does the ammeter do at higher RPM.
 
What does your Ammeter show, discharge or charge, under these conditions?
If it is in discharge at idle and no flicker I would suspect the alternator.




This makes me feel like there is a LARGE draw during the revolutions of the engine, or the output from the alternator is not being rectified correctly.

As asked earlier what does the ammeter do at higher RPM.
I’ll have to start the car and check that , will get that info during the week
 
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