Voltage Regulator Again?

[OldChargerGuy]

Greetings from West Virginia.

 

I am dealing with a charging system problem in a 1966 Dodge Charger. It carries a 361cid V8 bolted to the A727.  In 1974, a 4-bbl intake manifold and carburetor was installed. Otherwise, it's bone stock. In the past 2 years, voltage regulators have been failing often. Is this a manufacturing problem since the COVID pandemic? Is anyone else losing voltage regulators more frequently than oil changes? 

 

If not, here's some history on the three main electrical parts: battery, alternator, voltage regulator.

Aug 1999   new voltage regulator

[ purchased from older brother in 2003; detailed records since 8/02/2003 ]

Oct 2013   new battery

Apr 2015   new alternator

Jul 2020   PerTronix electronic ignition installed (not so bone stock now; this is the first modification since 4-bbl)

Nov 2020   new battery

May 2021   new voltage regulator

May 2022   new voltage regulator

Aug 2022   new voltage regulator

Nov 2022   last cruise, amp gauge measures discharging condition. Cover for winter.

 

I haven't diagnosed the problem this time yet; just asking if anyone else is having a lot of recent voltage regulator problems. 

 

The history points to the electronic ignition. I have no problem restoring the points and condenser if that's necessary. I am disappointed with that electronic ignition, anyways; it didn't improve performance or economy. And, yes, the battery that came with the car lasted over 14 years. They don't make 'em like they used to, eh?

 

The car uses an over-the counter alternator from NAPA, it's a square-back alternator. I understand that square-backs have an internal voltage regulator. This Charger, of course, has the shiny black voltage regulator on the firewall, still in service. Is this a conflict? Should the external regulator be by-passed? Should I begin searching for a round-back alternator?

 

This antique car is used regularly from April to November, clocking about 1,200 miles per year.

[Bloo]

One thing I see offhand is the squareback (1971 and later) alternator. They don't have an internal regulator, they use a firewall mounted electronic regulator and different wiring. To use it with the 1966 regulator and wiring, you'll need to ground the second brush, seen in your second picture. It won't charge until you do.

 

How many amps is that alternator? I can't tell from the pic because they all look alike. Originals were 32-35amp (no A/C) and 43-45amp (about) with a double pulley on cars with A/C.

 

One thing you should be aware of is 60 amp alternators are pretty common among the rebuilt ones, but weren't common at all among originals. A 60 amp alternator will burn up or melt the bulkhead connector on the firewall. Buyer beware. Factory 60 amp charging systems were only on police package cars and by special order. They had separate wiring through the firewall for charging, so they didn't use the bulkhead connector for that.

 

[JACK M]

Couldn't say about the charging problem, but the OEM style electronic ignition is a way better system the "P" word.

Your 361 is a "B" block engine.

 

Proform Parts 440-427 Proform Mopar Licensed Electronic Distributor Conversion Kits | Summit Racing

[DB26]

3 hours ago, JACK M said:

Couldn't say about the charging problem, but the OEM style electronic ignition is a way better system the "P" word.

Your 361 is a "B" block engine.

 

Proform Parts 440-427 Proform Mopar Licensed Electronic Distributor Conversion Kits | Summit Racing

Not to derail the conversation, but I am a points person as well. How do I convince others the “P” word is not worth it? Trying to get my dad to stop buying them. 

[Brooklyn Beer]

I have been running the P word in my 63 Dodge now for 6 years and in a 65 Fury, 46 Dodge, 49 Buick Roadmaster and 39 Chrysler without a hiccup.  If they fail I have AAA premium. I have blown out brake cylinders, voltage regulators, alternators, and an assortment of other things that have left me stranded. But never a pertronix.

[OldChargerGuy]

4 hours ago, Brooklyn Beer said:

I have been running the P word in my 63 Dodge now for 6 years and in a 65 Fury, 46 Dodge, 49 Buick Roadmaster and 39 Chrysler without a hiccup.  If they fail I have AAA premium. I have blown out brake cylinders, voltage regulators, alternators, and an assortment of other things that have left me stranded. But never a pertronix.

Thanks, BB. Your experience is appreciated. 

I love that '39 Beauty.

[OldChargerGuy]

7 hours ago, DB26 said:

Not to derail the conversation, but I am a points person as well. How do I convince others the “P” word is not worth it? Trying to get my dad to stop buying them. 

Thanks for the link, DB26. I will check the system out on Summit.

[OldChargerGuy]

On 2/8/2023 at 9:54 PM, Bloo said:

One thing I see offhand is the squareback (1971 and later) alternator. They don't have an internal regulator, they use a firewall mounted electronic regulator and different wiring. To use it with the 1966 regulator and wiring, you'll need to ground the second brush, seen in your second picture. It won't charge until you do.

 

How many amps is that alternator? I can't tell from the pic because they all look alike. Originals were 32-35amp (no A/C) and 43-45amp (about) with a double pulley on cars with A/C.

 

One thing you should be aware of is 60 amp alternators are pretty common among the rebuilt ones, but weren't common at all among originals. A 60 amp alternator will burn up or melt the bulkhead connector on the firewall. Buyer beware. Factory 60 amp charging systems were only on police package cars and by special order. They had separate wiring through the firewall for charging, so they didn't use the bulkhead connector for that.

 

Hey, Bloo. That alternator is a 35 amp remanufactured from NAPA, part number 213-1001. I had to dig out the invoice and check to be sure. It's also listed as an 'external regulator' type. 

The naked terminal on the back of the alternator caught my eye while recording the photograph. I'll look around carefully for a lonely wiring clip dangling nearby all alone. 

I sure am grateful for your advice.

[Bloo]

You'll have to make your own lonely wiring clip I think. Those small terminals are on the brushes. When the brushes wear out, they can be changed without taking the alternator apart. In 1966, the second brush screwed directly to the case. Later on the second brush was insulated and there was a second wire because the 1970s-era firewall mounted electronic regulator needed it that way.

 

The 1966 regulator needs that second brush grounded. Hook a wire to that extra terminal and ground the other end. If I remember correctly there's a screw hole on the back somewhere you can use for a ground, but I don't see it in the picture. If there's no screw hole handy on the back, run your ground wire around front and put a ring terminal around one of the bolts that holds the case together.

[22touring]

OldChargerGuy, I have 3 old Mopars from the '60s & '70s, and have had similar problems. At the risk of wasting a little of your time, here's my "shotgun" approach:

 

Check all the existing wiring carefully for shorts to ground, possibly intermittent ones.

 

Make sure that the engine, negative battery terminal, K-frame, body and dashboard are all well-grounded to each other by checking for voltage drop while loading the circuit. (It's all well and good when your ohmmeter shows good continuity, but ohmmeters are low-current devices, so they will not tell you if there is a voltage drop under load.)

 

Bypass the bulkhead connector by removing the existing "Packard"-type spade connectors, drill the bulkhead connector out large enough to clear a 12-gauge wire, and wire straight through the bulkhead connector on the two main high-current circuits: the one coming from the alternator and battery to the ammeter, and the one going from the ammeter to the main supply circuit splice. You may have a third high-current circuit on your car; if you do, bypass the bulkhead connector on that one, too.

 

Check your ammeter to make sure it has continuity under a loaded circuit.

 

The alternator's excitation coil is ground-side switched by the voltage regulator.  Make sure that the V.R. is only grounding that side of the excitation coil when it is trying to charge the battery, and that the ground side of the excitation coil is floating above ground when the V.R. is not charging.  When the excitation coil is on, is the alternator providing the battery with about 14.5 volts or so? 

 

Remove the V.R., sand to bright metal the areas where it contacts the bulkhead on both the V.R. and the bulkhead, and perhaps apply a little silver conductive paste to those areas.

 

Check the V.R. connector from the wiring harness for dirt, corrosion and pin-fitment issues.

 

Try another, known-good, V.R.  There are a lot of defective Chinesium parts coming through these days.

 

Hope this helps.

[OldChargerGuy]

On 2/10/2023 at 9:28 AM, 22touring said:

OldChargerGuy, I have 3 old Mopars from the '60s & '70s, and have had similar problems. At the risk of wasting a little of your time, here's my "shotgun" approach:

 

Check all the existing wiring carefully for shorts to ground, possibly intermittent ones.

 

Make sure that the engine, negative battery terminal, K-frame, body and dashboard are all well-grounded to each other by checking for voltage drop while loading the circuit. (It's all well and good when your ohmmeter shows good continuity, but ohmmeters are low-current devices, so they will not tell you if there is a voltage drop under load.)

 

Bypass the bulkhead connector by removing the existing "Packard"-type spade connectors, drill the bulkhead connector out large enough to clear a 12-gauge wire, and wire straight through the bulkhead connector on the two main high-current circuits: the one coming from the alternator and battery to the ammeter, and the one going from the ammeter to the main supply circuit splice. You may have a third high-current circuit on your car; if you do, bypass the bulkhead connector on that one, too.

 

Check your ammeter to make sure it has continuity under a loaded circuit.

 

The alternator's excitation coil is ground-side switched by the voltage regulator.  Make sure that the V.R. is only grounding that side of the excitation coil when it is trying to charge the battery, and that the ground side of the excitation coil is floating above ground when the V.R. is not charging.  When the excitation coil is on, is the alternator providing the battery with about 14.5 volts or so? 

 

Remove the V.R., sand to bright metal the areas where it contacts the bulkhead on both the V.R. and the bulkhead, and perhaps apply a little silver conductive paste to those areas.

 

Check the V.R. connector from the wiring harness for dirt, corrosion and pin-fitment issues.

 

Try another, known-good, V.R.  There are a lot of defective Chinesium parts coming through these days.

 

Hope this helps.

Wow. Your detailed knowledge is so appreciated, and a lot to take in all at once. Forgive me, but I struggle with automotive electricity and electronics. 

I would enjoy watching you do these diagnostic procedures, not to just watch good work, but to apprentice your knowledge.

Thank you.

[Bloo]

On 2/10/2023 at 6:28 AM, 22touring said:

The alternator's excitation coil is ground-side switched by the voltage regulator.  Make sure that the V.R. is only grounding that side of the excitation coil when it is trying to charge the battery, and that the ground side of the excitation coil is floating above ground when the V.R. is not charging.  When the excitation coil is on, is the alternator providing the battery with about 14.5 volts or so? 

I hate to be "that guy", and your post is otherwise full of excellent advice, but this part is just plain wrong.

 

1960-1969 Mopar alternator systems with the old "roundback" alternators charge by sending 12v to the field. One small wire comes from the regulator and connects to one brush. The second brush is grounded. On a 1960-69 roundback alternator, that second brush screws right to the case.

 

In 1970, they started using an electronic regulator (the flat "potted" one with the 3 pin plug). That one does ground the field to charge. A new roundback alternator case was made with the second brush floating to allow the use of this new electronic regulator that grounded the field to charge. There were now 2 small wires to the brushes. It doesn't matter which is which. One of them 12 volt ignition hot, and the other was the "ground to charge" wire from the regulator. In 1971 or 1972, they started making squareback alternators (like the one on @OldChargerGuy's car). Since squarebacks began in 1971 or 72, after the regulator change, all squareback alternators have the floating second brush for use with the electronic regulator.

 

@OldChargerGuy's car is a 1966 (per the original post) and has a 1960-69 style regulator still (there's a picture of it). Only the alternator is the later style. You can see the green wire from the regulator connected to one of the brushes. The other brush is floating.  It cannot possibly work like that. The regulator will send 12v to the field to make the alternator charge, but the other end of the field (second brush) is floating so nothing happens. If he connects a grounded wire to that second brush it will probably just work.

 

Edited February 12, 2023 by Bloo (see edit history)

[22touring]

Thank you for correcting me, Bloo. Sometimes I should just keep quiet! I apologize.

[Bloo]

Oh , and don't keep quiet. Lots of good stuff in that post. 👍

 

[OldChargerGuy]

21 hours ago, Bloo said:

 

Thank you, thank you, thank you, gentlemen; and ladies if applicable.

Why do I bother with any other antique automobile forum? Here is knowledge, hands-on expertise, and courteous mentors; the latter being so appreciated as younger enthusiasts are taught the details of caring for these fine cars. I'm nearly 63 years old, so feeling young here concerns me; but that's not an automotive electrical issue. 

 

The Imperial Forum has a similar teaching atmosphere; I'll probably keep that one. Some forums are, you know, less civilized.

 

The Gray Ghost isn't likely to attend an AACA event this year (another 'father of the bride' $pring), but its been invited to shade in the Mopar Survivor Display at Carlisle. The ol' Charger was retired from HPOF after an accident in 2021, but it's more than 80% original by a large margin. When the Ghost returns to an AACA event, come visit the DPC display. For videos, visit YouTube's Old Charger Guy channel. 

 

Thanks again, Friends.

 

PS: The attachment shows the Ghost sporting its casual attire, incorrect Magnum500 wheels and radial redlines, used for touring and local events. Yes, I said 'attire'. 

[1966 Charger RT]

Greetings,

Hoping someone can offer some guidance on an overcharging issue.

1966 Charger with a 383 converted to electronic engine harness,

New wire harness under hood,

New Square back alternator,

Charges over 16 volts, I shut it down immediately so as not to burn up any wires.

Have checked grounds, all lights work perfectly. Body was media blasted so there is no rust anywhere.

New ignition switch and checked all wiring connections in bulkhead.

Have voltage drop to 10.6 with ignition on.

Does anyone have any thoughts?

[Bloo]

12 hours ago, 1966 Charger RT said:

New ignition switch and checked all wiring connections in bulkhead.

Have voltage drop to 10.6 with ignition on.

Does anyone have any thoughts?

Drops to 10.6 where? That could be a huge clue.

 

On these charging systems, both the original 1966 and the 1970-up electronic, the ignition switch is powering the alternator field and is also the sample the regulator uses to judge "battery voltage". A small amount of loss is unavoidable, but any loss in the ignition switch or wiring will cause the charging voltage to jack up to compensate, never mind what the battery sees. One caveat, if you are checking at the coil, that doesn't count. Coil voltage is supposed to be lower because of the ballast resistor.

 

Which regulator now? Do you mean it has the 1970-up electronic regulator with the 3 pin plug with 2 pins in it? Or, do you still have a 1966 style regulator with a spade lug and a binding post?

 

You need the body grounded whatever you have. I saw you checked grounding, but in 66, and many other years the body ground is a strap from the back of the engine to the firewall. Is it there?

 

The regulator needs to be well grounded to the body by it's bolts. Usually it's bolted to the firewall. Bolted down solid?

 

Assuming you now have the 1970-up electronic regulator, there needs to be 2 small wires down to the alternator now, where there was only one in 1966. They connect to the 2 small terminals. Important note: one small alternator terminal was grounded when using a squareback alternator with a 1969 and earlier regulator. Not anymore with the 1970-up electronic regulator. There is a second small wire now, and it is hot instead. I found this graphic online:

 

 

Important note: The blue wire connected to the "ballast resistor" is connected to the side of the ballast resistor coming directly from the ignition switch. It is direct key power. If by some chance you have an early 70s style 4 wire ballast resistor now, it is still true.

 

Ok, so the firewall ground strap is there, and making good connection. The regulator is well grounded to the body, and is getting it's power from the ballast resistor terminal that comes directly from the key right?  Separately disconnect each of the two small wires from the alternator, and verify that the alternator stops charging. Try them both. I don't really think it's possible you will find the trouble here, but if it passes this test the overcharging trouble cannot possibly be in the alternator.

 

Assuming it is wired like the diagram above (and you did already mention that the bulkhead connector is good), the regulator just about has to be bad.

 

Option 2: This applies If and only if you still have the 1966 mechanical regulator, or some aftermarket electronic direct-fit substitute for the mechanical regulator. Key power goes to the regulator's spade terminal, and the regulator's bolted terminal goes to the single small wire to the alternator, as original. One small terminal on the squareback alternator is grounded to make the squareback work in this system. Disconnecting the single small wire that comes from the regulator to the other terminal should make the alternator stop charging. If it does, the regulator probably has stuck points (or is just defective if it is an aftermarket electronic substitute).

 

Edited September 15 by Bloo (see edit history)

[1966 Charger RT]

Really appreciate the detailed explanation.

I do have the newer 2 pin regulator and the square back 2 field alternator.

I do have the ground strap from engine to firewall.

 

There are a couple possibilities that I have learned and will try out.

Will update in the next couple days.

Thank you!