New alternater & voltage reg - not charging

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Ken71Twister

Ken71Twister

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I've searched the threads looking for the same problem with no luck.

Here's what I can tell you. 1971 318 Duster. Wiring is original setup with some patches here and there thanks to a mouse that chewed wires a decade ago.

A week ago, I repalced a working 40 amp alternater with a 60 amp alternater because I suspected that the old one was making some noise. Otherwise - everything worked.

The new alternater has been taken back to the store and tested good.

The store also checked my battery with the car running and verified that it is good.

The belt is not slipping.

The voltage regulator is new and well grounded.

Battery grounds removed and cleaned yesterday.

field wire (green) fm alternater to the voltage regulator is good. Just in case, I made a jumper but it didn't make any difference.

the second wire at the regulater (blue) is hot with the ingition switch on and voltage is approximately the same as the battery. As near as I can recall, I think it was same at voltage measured at the battery or within 0.1V. I made a jumper here too directly from the battery - no help.

With car at idle, battery gauge on dash is barely left of center 'till I turn on headlights - then it shows large discharge. All indications are that I'm getting nothing from the alternater when connected to the voltage regulator.

I get similar results when I load the system with the wipers and heater fan.

Engine dies immediately when battery is disconnected. It will ordinarily continue to idle when the battery is disconnected.

If I unplug connector from the voltage regulator and jumper the green wire to the blue and then start the car - the battery gauge shows a good charge as I increase the idle.

I tried the old voltage regulator which worked before I replaced the alternator ( I drove car once with new alternater and old voltage regulater) and results are the same.

Am I missing something? Any reason why a good (well grounded) voltage regulater wouldn't work when a jumper gets the alternater to work?

For what it's worth - I've tried this with and without a battery charger attached to the battery. No difference. The engine starts and runs fine thru all this. Headlights are, of course, dim when I turn them on without the battery charger. The battery meter seems to be working fine.

I'm about out of ideas if I don't have two bad voltage regulators.
 
If you connect the 2 regulator wires together and get it to charge, Alt and wiring is good. I'd suspect the regulator.
 
Ken71Twister said:
Engine dies immediately when battery is disconnected. It will ordinarily continue to idle when the battery is disconnected.

If I unplug connector from the voltage regulator and jumper the green wire to the blue and then start the car - the battery gauge shows a good charge as I increase the idle.
Click to expand...

First, you should not ever disconnect the battery on a running engine. I wish I could lay this stupid procedure to rest.

Can or have you put the old one back on, and does it work?


You DO have the late model (70/ later) regulator, right? If so, making it charge by jumpering green to blue makes no sense, as it should not happen. Refer to the simplified diagram below:

Switched "ignition run" (battery) is fed to both the regulator IGN terminal and one of the two field terminals. That seems to check out, as you show battery there at the field.

So try this:

Turn the key to "run" disconnect the green field wire, and hook a clip lead from that brush terminal to ground. You should see a small spark as you connect/ disconnect the terminal in reduced lighting.

Now start the engine, bring up RPM, and see if it charges.

If not, measure voltage at the battery, then measure right at the alternator output stud. If voltage at the output stud is high, you have a break in the charging line. Since you had it apart, you may have broken the wire end connection in the molded end piece.

If it DOES charge, hook the green back up, go up and unhook the regulator and ground the green wire at the regulator connector. I don't remember, you can use 8 or 10-32 machine screws to make contact. Also examine the regulator connector for corrosion, and "work" it in/ out several times to scrub the contacts and to "feel" for tightness. Suspect that the contact may be broken in the wire/ molded end.

If ground that up at the regulator is OK, double check regulator ground. If that seems OK, now jumper the green/ blue together at the regulator.

Now take your clip lead, remove the blue field wire at the alternator and ground that field terminal. Once again, with key in "run," you should see a smalls spark. Once again, with the RPM up some, it should charge like mad.

If this much checks out, triple check regulator ground and then replace the regulator.

 
65Val said:
If you connect the 2 regulator wires together and get it to charge, Alt and wiring is good. I'd suspect the regulator.
Click to expand...

He should have a 70/ later regulator, (isolated field) and this 'should not' work.
 
Thanks for the suggestions. Maybe I'll come home at lunch time and re-read closely and try a couple of your suggestions. The car came off the production line 28 June 1971 - supposedly the last week the '71 production line ran. I've never intentionally changed anything - always bought parts for a '71.

The field connector on the alternator has a new clip/connector - but I'll check it today to make sure it is tight.

If the new voltage regulator is bad and the one that was working before the new alternater was put on a week ago is also bad - next problem will be to determine why they are bad. What are the odds that the old one dies and the new one is bad off the shelf?

tx for your help,
Ken
 
One thing I see in the schematic is that it shows a second field wire going to the ballast resister. I'll have to trace the wires from the ballast resister because there's only one small wire (green) coming off the alternater (and only one clip on the alternater). No blue wire with a tracer - although there is an unused blue wire near-by which is switched/hot and I've always assumed it was for an accessory that I don't have.
 
The blue wire is switched 12 volts under the hood. It branches to the alt', reg', and ballast resistor/ignition. Where the factory attached these branches and how many branches will vary from one year model to another.
If your voltage regulator has a blue wire in one end and a green wire at the other, your alt wouldn't have a terminal for a blue wire.
If your voltage regulator has a modular plug like shown in the drawing, your alternator should have a terminal for the blue wire.
 
If you only have one field clip and wire on the alternator it is an early style and needs a different regulator. The early style has one field brush grounded at the alternator, the other field connection gets source power from the regulator that is supplied from the ignition supply.

The newer style regulators are sinking, where one field connection is powered by the ignition, and the second one pulled to ground by the regulator. In both the regulator completes the field circuit momentarily as necessary to regulate voltage sensed on the ignition supply. In both cases, regulator case ground is important.

The change to a sinking regulator works better for a solid-state regulator, because transistors more readily switch to ground than to source to 12V.

There are also solid-state regulators for the old style that source, and ones can be found that even look old style.
 
Because the battery is a large storage source, it serves to filter the alternator output. Without it the alternator provides a rectified 3 phase voltage that is very bumpy, peaks greater than nominal 13.8V. It will easily damage electronic equipment it powers.
 
Check your bulk head connector to the make sure you a good contact on all of the terminals. I believe the load wire from the voltage regulator goes throught the bulk head connector to the back of the instrument cluster and then back out to the battery.
 
KitCarlson said:
Because ..................
Click to expand...

Thanks, Dave, but there's an even better reason that not blowing stuff up, LOL

(Actually, you COULD blow up a battery doing this, so think about THAT)

But this so called "test" which NObody will EVER find in any classroom, auto mechanics course, or shop manual, doesn't TEST anything.

Couple of examples:

Let's say you have a bone stock /6 or 318 stick, which idles nice and smooth, slow. You unhook the battery and the engine dies, and you incorrectly conclude that the alternator is bad. It just might be that depending on the load on the system, and the RPM the alternator was turning, it wasn't putting out anything, and was completely NORMAL

Next, let's say you have, say, a 60 amp alternator and FOUR of the six diodes are blown open. This means you have TWO diodes left, and this thing MIGHT be capable of outputting 20 amps. So what do you do? Why of course, you remove the battery cable AND IT RUNS JUST FINE. So in this case you incorrectly conclude th alternator is WORKING, yet at night with the lights and heater, etc going, the darn thing can't keep up.

So this test:

1--can blow up expensive electronics, including that great big "amp" in the trunk

2--can actually explode a battery (hydrogen, look it up)

3--this "test" doesn't prove one way or the other whether the system is working or not.
 
Advice accepted - I won't disconnect the battery again with the engine running.

I've followed a few of the steps above and measured voltage and resistance in a few spots. Seems that everything points to a bad voltage regulator - but I have a hard time believing that my old one suddenly went bad and then I bought a bad one.

One difference from the diagram above is that there is not a blue wire coming from the alternator - just a green one and a heavy black one.

With the switch on - the heavy black wire is 13.34 V.

The green wire from the alternator to the voltage regulator has a good connection at the alternator and my Sears digital meter shows one Ohm resistance from end to end.

There is no spark when connecting the green wire to the alternator with or without the switch on and with and without the engine running.

There is no voltage between the field connector (for the green wire) and ground. The meter shows 17.8 ohms between these two points. The ground to the alternator housing and to the engine block are the same.

I measured ends of the green and blue wires at the voltage regulator (unplugged) the the connection was open.

I measured across the two posts on the voltage regulator and these were open.

Once again, with the engine running, I used the probe from my meter to jumper the green wire to the blue wire at the voltage regulator (connector unplugged) and there was the predictable spark and the engine slowed slightly and the battery gauge on the dash showed that the battery was getting a charge.

I guess that I still need to trace the blue wire (with battery voltage on it) from the voltage regulator - but I don't know what to hope for there since I've measured a steady battery voltage each time I've checked it.

The green field wire to the black wire - both on the alternator - are an open circuit with the switch off and with the switch off.

Seems like it should work if the voltage regulater is grounded. The meter says it is gounded, the metal under the regulator is shiny and I even wire brushed the bolts that hold it on.

Reminder: The battery (not new but good) and the alternator both checked out as good on Saturday. Given the info I've provided, additional ideas before I roll the dice and buy another voltage regulator?

tx,
Ken
 
OK, if you only have two wires on the alternator, either you have misplaced one, or someone has converted the thing to the 69/ earlier system.

What does your regulator look like?

SHOULD be this:

a6473a71398477cdaff217_m.JPG


and it should follow the diagram I posted above. Your alternator SHOULD have two field connections, like this:

PaXFEegBYxGGogC.jpg


or this which is an inferior 70 version

attachment.php


Now if your regulator looks like this:

Someone has "converted" your vehicle to the 69/ earlier regulator, and you may also have the early alternator, with only one brush / field connection

440-1619-thickbox.jpg
 
Once again, with the engine running, I used the probe from my meter to jumper the green wire to the blue wire at the voltage regulator (connector unplugged) and there was the predictable spark and the engine slowed slightly and the battery gauge on the dash showed that the battery was getting a charge.
Click to expand...

If this is so, then your alt is OK, because you are charging when jumping the regulator.....replace your regulator again...hopefully getting a good one this time. You can buy brand-new, faulty parts you know.
 
65Val said:
If this is so, then your alt is OK, because you are charging when jumping the regulator.....replace your regulator again...hopefully getting a good one this time. You can buy brand-new, faulty parts you know.
Click to expand...

We need to stop jumping to conclusions. He either has the wrong alternator (and possibly regulator) which is going to affect test procedures, or is missing the second field wire, or maybe even has a "mix and match" of early / late componets. '

On top of those possibilities, there might actually be some problem, LOL.
 
If it charges when he jumps the regulator, and he says it does, then everything else is OK, and its the regulator thats faulty. I believe we're overthinking this.

A known good regulator should fix it.
 
I disagree. He says he replaced the alternator. If he either got an early alternator on there, or else got a late one with a shorted field terminal, then it would "act like" an early alternator. Then, assuming it has a correct 70 regulator, it won't work. But jumpering the two terminals would cause it to charge.

He should not HAVE the early system, and therefore jumpering across the regulator terminals should NOT cause a charge situation.

Just one scenario. I'm sticking to my guns.

FIRST ORDER OF BUSINESS is to discover what "equipment" we are dealing with.

Second is to figure out what's wrong, whether incorrect (late/ early parts) or a defect in one of those parts.
 
I'll take pictures. I'm dealing with Advance Auto Parts store and the parts are what their computer specifies. I was back there (at the store) again last night. The alternater does not have the second field connection shown in the picture above.

Wish I could stay home and work this - but guess I should be glad to have a job to go to. Working on the car would be more fun.

tx,
Ken
 
Just a suggestion (because I have done this before) when you install your regulator the battery must be disconnected and the regulator must be mounted (grounded) before any of the wires are connected to it. I dealt with a similar problem and I ended up not having the regulator grounded when the wires got connected and blew the new regulator. Put another New one on the right way and haven't had an issue since.
 
Ken71Twister said:
I'll take pictures. I'm dealing with Advance Auto Parts store and the parts are what their computer specifies. I was back there (at the store) again last night. The alternater does not have the second field connection shown in the picture above.

Wish I could stay home and work this - but guess I should be glad to have a job to go to. Working on the car would be more fun.

tx,
Ken
Click to expand...

Good plan. Starting to sound like you have an incorrect "early" alternator.
 
aprfcto - Thanks for sharing the fact that the voltage regulator can be ruined if not grounded before any wires are connected. I know that I've done this to both regulators at one time or another. I can't be sure that I didn't hook it up before I gounded it the first time. That's good news because, otherwise, I couldn't figure a reason for having two regulators go bad the same week.

67Dart273 - The voltage regulator in the picture you provided looks the same as my new and old voltage regulator. As I said earlier - the alternator is different - it only has one field connector that the green wire goes to. The voltage regulator boot has a green wire (leading to the alternator) and a blue wire that disappears onto a factory wire bundle. My Chilton's shows the same alternator that you show with two field leads. I've had the car almost 42 years and have been through several alternators and it has been in the shop a few times - so I can't be sure that I never had an alternator with two field wires.

Now that I have a plausible explaination for how two voltage regulator could have been messed up - I'm comfortable with getting another new voltage regulator and I'll report back. I'll be very sure to install/ground the next one before I connect any wires.

tx again,
Ken
 
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