VCCA Home Forums GENERAL DISCUSSION New User Forum 1950 Chevy Deluxe Alt Not Charging

Hello,
This is my first post and looking for assistance with my 1950 Chevrolet Deluxe. This is an all original vehicle still on the 6 V system. The Alternator is not charging the battery. The volt meter in the car stays at the midpoint while running and drops down to the negative when the lights are on. This issue just started a few days ago. Normally when driving the volt meter shows in the positive range when running at higher RPM, but in the last few days it does not move above the mid point. I was out for a drive and the stopped to get gas and when trying to start it would not turn over. I had the car towed home and realized the battery was nearly dead. I charged it and let it run for a while and it eventually stopped running. The battery was dead again. When I disconnect the negative terminal the car stops running. I replaced the alternator and the issue continues. will run for a while until the batter runs down then the car stops. The voltage regulator looks new. Looking for help on trouble shooting or suggestions as to why the alt is not getting the charge to the battery.
Thank you in advance for your input and suggestions.

Hi There and welcome to Chevy Chatter.

In your post you mentioned several times that your car has an alternator. Do you actually have an alternator or do you have a generator? You said that your car is all original so it should have a generator instead of an alternator. It sounds like you have an issue with your voltage regulator. Check your shop manual and it will tell you how to test the voltage regulator to see if the issue is actually with the voltage regulator itself.

Thank you JY Dog. It is an alternator a Remy Delco, your right if it was 100% original it would have the generator. The car has original engine, wiring, tranny etc no modifications. I will look for info on checking the voltage regulator to see if I can find an issue there.

probably your alternator has a built in regulator. Sounds like it would be best to remove and have it checked at a repair shop.

Quick update, the alternator is charging. I disconnected the 3 wires on the voltage regulator and sanded down the contacts. Started it up and good to go! Must have been some corrosion on there interrupting the circuit. Thank you for the input above, very much appreciated.

Well I'm back a few months later with the same issue. The alternator I put on in March didn't last long....it was not new but one that I had laying around the garage. It is putting out about 1-2 volts.
What clued me into the issue is this week I went for a drive and when I turned the lights on the Ammeter pegged to the far left on the minus side. Despite driving and revving the engine there was no movement to the right. When I turned the lights off, the needle moved back to dead center. Prior to this event when I put the alternator in, the meter was showing a positive charge, would dip a bit with the lights on to center at idle, but would move to the plus side while driving.

I have ordered a new 6V alternator from the Filling Station that should arrive in a few days. As I noted above, I replaced the alternator back in March and still had the issue. I cleaned up some contacts on the wires going to the box which contains the Circuit Breaker, Voltage and Current Regulators which is mounted on the inside of the engine compartment behind the instrument panel. After cleaning the contacts, I started getting a charge. Now that the alternator is kaput, no charge. And I rechecked the wire contacts and they are good.

I'm being proactive in asking the question, when I put the new 6V alternator on and if I'm still am not getting a charge, are there any suggestions?

I do have the shop manual and have the instructions to check the voltage regulator, but honestly its not super clear to me how to test it. The manual references some checks but they seem to be related to a Generator hook up and not an alternator hook up ( 2 wires vs 3 wires on the alternator) In looking over the instructions in the manual to check the Voltage Regulator, the manual says to disconnect the BAT wire from the BAT Terminal on the box, hook up an ammeter to check voltage between the box and the BAT wire. On my car there is not BAT wire going into the box. I only have the Generator and Field wires connected.

Thank you for any input and things to check.
Regards,
Mal

The regulator is for the generator not the alternator. Most alternators have a single wire and an internal regulator so the one for the generator is bypassed and not used. If you have the three wire alternator then a special regulator is needed for it.

Most alternators have 1 wire that connects the battery (via ignition switch and charge light) to the field and and another wire to the battery via the ammeter (this can go to the main connection of the starter).
Tony

Thank you Tony and Chipper for the inputs, good points to look at. The alternator will arrive in a week or so. I'll report back what I find out.
Regards,
Mal

I put the alternator in today. Its a 6 V Alternator from the Filling Station. I checked output voltage by touching positive lead to the primary output on the back of the unit (Bat) Wire and the negative lead to the housing of the alternator and have 8.4 volts. I expected greater than 6 so this seems to be working well.
I checked the cables on the battery while the car is running, but only have 6.22 Volts. I was expecting to see similar 8 volts going into the battery. Maybe I'm wrong on this check, but seems like the connection from the Alt to the battery is not working. Also, when I take the Neg cable off, the car dies. I was expecting the new Alt to keep it running with the batter disconnected. With the car on and the lights on, the meter on the dash goes to the negative, near the far left side. Turning on the radio and the blower drives it all the way to the left in the Neg zone. No change when revving or driving the car at higher RPM. During normal driving the needle stays dead center. It never moves past center into the POS range. My concern is continuous driving will ultimately run the batter down and I'll be stuck with a dead battery. This is what lead me here to VCAA chat in the first place.
Question to the smarter folks than me, should the ammeter on the dash show in the POS range?
Is it normal to have the needle peg hard in the NEG when the lights come on?

I tried combinations of taking the field wires off of the Alt, 1, then both, then the other one, but the changes had no effect. Also, I'm not 100% sure that the old Voltage Regulator is actually being used at this point, altough it does have two wires going into the contacts in the middle and the right. There is nothing connected to the BAT terminal on the votlage regulator.

Looking for input if my checks are correct to determine if the batter is actually getting the charge and for input on the function of how the ammeter in the dash is supposed to behave.
i'm not an expert, I have the shop manual, but admit I don't know what Normal is supposed to look like.
Thanks!

Hi Mal,

You will probably not like my recommendation, but I am going to give it anyway. I suggest you dig your GENERATOR out of the corner of the garage, get it PROFESSIONALLY rebuilt. Install the generator and either you with the service manual or a reliable person to set the voltage regulator. Perhaps you just expect too much from your 1950 car. I have a 1950 Styleline Deluxe 4-door and a 1950 Styleline Deluxe Convertible, both vehicles are still on 6-volts and have the original set up with the generator and voltage regulator. I keep everything well maintained and have no problems with the operation of either car.

If you still have problems, come on back here and we will help you find the problem and fix it.

I agree with Ray, keep it as close to original as possible it worked for a lot of years.
By what you are saying I suspect you still have the original regulator in circuit, if this is the case disconnect it. Determine which wire comes from the output of the now alternator and which 1 goes to the ammeter on the dash and direct connect them together.
Tony

Madman50: The alternator from TFS most likely has a self engergizing 1 wire internal regulator.If so just connect the battery wire from your original regulator to the large post(battery terminal) on the new alternator.If the rest of the wiring is still correct you should be good to go
davids---good luck---

I agree that it sound like you do not have the wiring correct. You need to confirm if that is a one wire (self energizing) alternator. Even is it is not self energizing it will be internally regulated and you will not use the regulator that was needed with the generator. You need to do some research to determine how to connect it.

Also, I would be concerned with an output of 8.4 volts. That is a lot for 6 volt components. It is possible that you were reading an unregulated voltage within the alternator.

I would expect that a well regulated 6 volt alternator would produce about 6.8 to no more than 7.2 volts.

I agree with Rusty 37 Master. If we are talking about the regulator box on the firewall that came with the generator, that is not used with an alternator at all. If it was an externally regulated Alternator (extremely unlikely in 2019), it would need it's own little regulator box on the firewall.

8.4 volts is too much.

It might help to understand how this works. There are 3 relays in the stock regulator box. They are:

1) Cutout

2) Current Regulator

3) Voltage regulator.

In an alternator system the:

1) Cutout is not used. It's whole purpose is to keep the generator from becoming damaged from trying to run like a motor when it isn't charging, and to keep it from draining the battery. Diodes in the alternator provide this function by default.

2) This one is not used either. A DC generator will happily charge way over it's rating and burn up if something (like a discharged battery) draws too much current (too many Amps). The Stator in an Alternator is made in such a way that it self-regulates. It will go right up to it's rating when asked, and then just stop there, all by itself. Nothing else is needed.

3) This is also not needed. Alternators do use this one, and for an externally regulated alternator it might be possible to scab this one into the circuit, but 99.9 percent of the time these days, there is a regulator built in to the alternator, and it wants nothing to do with any outside device.

On a "one wire" alternator, it goes like this:

On a car with an idiot light, there is a heavy piece of wire from the big terminal to the battery. The connection to power the car can be anywhere along this wire. There is also a terminal to connect the idiot light.

On a car with an ammeter, the big wire goes from the alternator to the ammeter, and then another wire from the ammeter to the battery. The connection to power the rest of the car goes to the Alternator side of the ammeter.

And i don't mean this as any kind of a slam, but if it were mine, I would also just put the generator back on. Those early 50s Chevrolet systems were 40 amp IIRC, and can do anything an Alternator can do, except charge really hard at idle. That doesn't really make any difference in the real world, unless you are sitting for long periods in stop-and-go traffic with the headlights and a bunch of accessories running. I have never had as much trouble with one of these particular generator systems as you have already had in this thread. I have never been towed because of one.

Best of luck whatever you do.

To all,
thank you for the inputs, comments and suggestions above. I will investigate the suggestions on wiring connections etc. Very much appreciated.
I've had the car for 6 years, when I purchased it, it came with an alternator installed. In the trunk were a number of old generators which I can look into having professionally rebuilt. Since it had an Alt on it, I chose to replace with an alternator. You've all made good points.
I have had some recent issues with the turn signals and horn not working which was related to the old cloth-type wiring fraying and causing shorts. With the routing noted above on the wiring, I may have an issue with a bad wire. It is all original wiring.
I'll do some checks and traces and see what I can find out and will share the results. Thanks again to all for the input, really really appreciate it.
Regards,
Mal

Hi Mal,

Your last post added a key piece of information we did not know. If the original harness is failing that will create problems you will have much difficulty troubleshooting.

I strong recommend that you never the leave the battery connected when you are not with the car and that you keep a fire extinguisher handy. Replace that original harness completely as soon as you can.

It would be a real shame to lose the car and possibly the garage due to a fire caused by an electrical short.

Rusty, great point! Im going out to disconnect the cable now. I do have an extinguisher in the car. Never know what can happen, short, fuel leak etc.
I traced some of the POS wires going from the battery to the starter and in to the Ammeter, but ran out of daylight and time to trace the other side which leads towards the alternator. I've cleaned an number of ground wires when I had the turn signal issue, but never cleaned up the POS wires that seem to converge at the starter then branch out from there. I read on another post somewhere on this forum about resistance on the POS side due to corrosion which could hamper the overall circuit, so I'm going to check those connections tomorrow.
More work, reading and investigating to do so I'll post back in a day or two on the results. Agree about the harness, when I found the frayed points on the turn signal column and some other areas the thought crossed my mind that replacing some of those wiring harnesses may be the next project.

Mal, I would highly recommend that you bite the bullet and replace the complete wiring harness. Working with 70 year old wiring is as futile as trying to put the toothpaste back into the tube. You'll fix one section and another one lets go. There could be any number of places where the insulation has deteriorated or disappeared, letting a bare wire contact metal (e.g wiring in the roof, front end, trunk, or running along the floor). Just a suggestion!

Hi Mal,

The first time I saw my '37 up close in December, 2006 I promised that I would not connect a battery to it until I had installed a new harness. It was approaching 70 years old and every time I touched a wire the insulation broke away.

Even worse is that later I discovered that someone had replaced the one fuse in the car with a short piece of 1/4-20 threaded rod.

YNZ and Rhode Island Wiring both make excellent reproduction harnesses. It is the cheapest insurance you can buy to make your car safe and reliable.

Thanks Rusty and Kaygee, I'm going to start looking into the harnesses. I think its time. I still have some more checks to do this weekend on the current, no pun intended, issue and will report back what I find.

Good day to all. Problem has been solved! Before I explain, thank you to everyone for you comments, suggestions and recommendations. The combined input from everyone lead me to the problem and solution. Hopeful that any future visitors who have a similar problem find them selves reading this thread and can get the the solution faster and sooner than I did.
Just to recap the problem, without warning, the Ammeter started pegging hard in the - side when the lights were turned on. They went low with the running lights and even lower when the headlights were on. It was apparent the alternator was not charging. Just to be clear, this is a 6 Volt system with an alternator. My original assumption is that the alternator on the car was bad, when I checked voltage output it was well below the 7+ volts I expected. I replaced the alternator and had success for a few months. Then one day, about 4 months later, the Ammeter started to peg hard to the - side.
I bought another Alternator and still had the same problem. Voltage on the new 6V alt from The Filling Station was putting out 7.2V. The ammeter was reading dead center during running, It would dip down and move with the turn signals, then return to center when the signals were turned off. Same activity when I pressed the brake pedal, it would dip down a tad then return to center. The problem is it would never go past 0 into the Positive range. Always a draw on the battery. The problem caught up to me when I stopped for gas and did not have enough battery power to start the car. In summary, the battery was slowly being run down while driving.
As I said, this car has an alternator, not the original generator. It was like that when I bought it 6 years ago.
It was apparent after multiple tests with the volt meter that the charge from the Alt was not making its way to the Ammeter to flow back to the battery. When converting from the Generator to the Alternator, the wire that connects to the BAT on the voltage regulator is connected to the BAT terminal of the Alternator and then runs directly to the Ammeter. Thanks to the diagram that came with the new 6V alternator from The Filling Station, it showed how to reconnect those wires.
The wiring bundle had been re-wrapped with what I would call hockey stick tape. It looked good and tight, but I could not see the splice to make the connection between the BAT wire from the Voltage Regulator and the wire coming off the BAT terminal of the alternator.
I unraveled the tape and there was the problem! The splice between these two wires was completely corroded and non existent. The connection was very short to begin with some time in the past, not much overlap between the two wires at all. Over time the wires literally corroded apart. There was no connection at all! As soon as I saw this it was evident the charge from the alternator was not making its way to the Ammeter. The result is the battery was not being charged at all.
I cleaned up the wire ends and added a 10G wire splice to fill the gap. I started the car the Holy Cow! The ammeter immediately moved to the Positive side showing a charge! Turning on the lights dropped it a bit, but the ammeter still showed slightly on the POS side.
So, in summary, a corroded wire connection was the problem. The charge from the ALT was not making it past this broken connection.
Thanks to everyone for the inputs. After taking your inputs, looking at the wiring diagram in the shop manual, it was apparent the flow from the ALT to the Ammeter was interrupted and the problem was a corroded splice. To me, this car has had an ALT for at least 20 if not more years. Over time that splice just wore out.
If your here looking for a solution to this same Ammeter problem and your using an ALT and not the original Generator, then follow that wire all the way into the Ammeter. You may find a similar problem.
Very happy I can drive in confidence now and not worry about having to be towed next time I stop for gas. This forum is awesome! Lots of great folks who are open to lending a suggestion or recommendation to help a fellow car guy or gal out.
Regards,
Mal

Glad you got it fixed!

Bloo your 1,2,3, summary above about the Alternator System was really key, especially this point below. Overall these systems are pretty simple and straight forward. The more I kept thinking about how the system is supposed to be wired, I knew that portion of the system going from Alternator to the Ammeter was not right.
I was hesitant to start taking the bundles apart, but that is what was needed to find the problem.


"On a car with an ammeter, the big wire goes from the alternator to the ammeter, and then another wire from the ammeter to the battery. The connection to power the rest of the car goes to the Alternator side of the ammeter."