Not charging - even with new alternator, battery and regulator

[AztorTheSailor]

Hello.

A couple of months ago I made the stressful mistake to fill my Dodge Monaco 1971 model with diesel.
I had it into a quality garage here in Norway, they changed the battery, plugs and gasolin filter, and of course flushed the system.
I got the car after a couple of days, drove home, next day when I was at the mall, it would not start after going home again. It turned out the battery was flat, after testing with meter I found out there was no charging.
So I bought a new alternator and regulator, putted them in today, started up, all looked good on the meter (14-16 on the meter after a minute), then it went down to 11-12 and after a while, battery was flat again. No charging.

Could I have fryed the regulator in some way?
Or what could it be?
Hope for some advice. Thank you in advance from Norway.

 

[Yeahrightgreer]

Check your connections at your bulkhead connector. Make sure they are not corroded or dirty.

check your grounds and clean surfaces from battery terminals to grounds. The voltage regulator grounds to the firewall so ensure that surface is clean. I’ve seen regulators be defective out of the box but let’s assume it’s not that.

check wires. Take your meter and test for voltage starting at the battery. Try at the starter relay. Then to the regulator and to the alternator. Check if you are losing voltage - or if you have none at all.

Jiggly your wires throughout the circuit with a mulitmeter connected and record your MAX voltage. If it randomly starts charging - it’s your wires

 

[Yeahrightgreer]

Keep us posted

 

[AztorTheSailor]

Thank you for taking your time to reply.
I will try all these things tomorrow, midnight here now.

Check your connections at your bulkhead connector. Make sure they are not corroded or dirty.

check your grounds and clean surfaces from battery terminals to grounds. The voltage regulator grounds to the firewall so ensure that surface is clean. I’ve seen regulators be defective out of the box but let’s assume it’s not that.

check wires. Take your meter and test for voltage starting at the battery. Try at the starter relay. Then to the regulator and to the alternator. Check if you are losing voltage - or if you have none at all.

Jiggly your wires throughout the circuit with a mulitmeter connected and record your MAX voltage. If it randomly starts charging - it’s your wires

 

[1970FuryConv]

You could trying running a ground wire from one of the VR mounting bolts to the engine block. As Greer pointed out, voltage regulator must have good ground.

 

[Davea Lux]

You might also check to see if there is power to the field connection for the alternator, it (alternator field) needs to be energized for the alternator to charge.

Dave

 

[Gerald Morris]

Given how RAPIDLY this has occurred, I suspect you have a SEVERE SHORT more than a CHARGING PROBLEM. Look, I've driven my own ride, a 66 Newport w a 383 with a TOTALLY DEAD ALTERNATOR for a good half hour without significantly draining the battery. I've done this once in rain, and once in dark at night. In both instances the aged battery retained enough charge to start the engine once I had replaced the alternator (the night instance) or let the alternator DRY OUT after it was immersed in a flooded street intersection.

The only thing I can think of that would drain your battery so quickly would be a short in the main starting circuit. Check the starter and solenoid out at once! Look for a short on that BIG RED WIRE from the battery to the starter. See if the solenoid itself is sticking somehow, electrically and draining your battery.

Look for signs of high heat near this system too. A big short will be accompanied by big heat.

How long did you run the engine and watch the voltage drop so precipitously? THAT DATUM is CRUCIAL to solving this problem.

 

[AztorTheSailor]

This could be the problem.
After my uncle and his buddy (who both are electricians and good with engines) puttet on the new alternator and regulator, I started up the engine, the voltmeter was showing 14-16 the first minutes, then it went down to 12,6-12,8 for a long while, while engine was running. It was not going down much, but each time I did a restart of engine since they tested different grounds/connections with the voltmeter, we heard the start engine struggled more and more to start, and at 3rd start, there was not enough power to start the car.
Had to charge battery from another source so I could drive home (since it was getting so late).
So it is like you say, I can drive for a good while, but when I stop and start engine, it is then the battery goes very fast down in power.
As a sidenote, when I bought the car, there was a 70 amp battery in it. The garage took it away and putted in a 60 amp (540) battery. We was agree yesterday that it is maybe a small battery for that engine (440 -7,2 litre).

Given how RAPIDLY this has occurred, I suspect you have a SEVERE SHORT more than a CHARGING PROBLEM. Look, I've driven my own ride, a 66 Newport w a 383 with a TOTALLY DEAD ALTERNATOR for a good half hour without significantly draining the battery. I've done this once in rain, and once in dark at night. In both instances the aged battery retained enough charge to start the engine once I had replaced the alternator (the night instance) or let the alternator DRY OUT after it was immersed in a flooded street intersection.

The only thing I can think of that would drain your battery so quickly would be a short in the main starting circuit. Check the starter and solenoid out at once! Look for a short on that BIG RED WIRE from the battery to the starter. See if the solenoid itself is sticking somehow, electrically and draining your battery.

Look for signs of high heat near this system too. A big short will be accompanied by big heat.

How long did you run the engine and watch the voltage drop so precipitously? THAT DATUM is CRUCIAL to solving this problem.

 

[Big_John]

You've thrown a bunch of parts at the problem without figuring out what the problem was to begin with. That brings a bunch more variables into the mix.. Now you may have "new" parts that aren't right.. or a bad installation etc. I don't understand why they put in a new battery after the diesel incident, but that may be indicating there was an issue or they just wanted to sell you a battery.

First thing I would do is disconnect the new battery and charge it. Do a voltage check once it's done and be sure it's at about 12.5 volts. A battery tester would come in handy if you have one. These sell in the states for about $20.

Since I agree that it does sound like some sort of short, you can do some fairly easy testing of that with a DMM.

This guy goes over a simple way to check. Pay attention to the first half of the video.



He shows some other methods and a better method for diagnosing at the fuse panel on this video.



From there, a look at the service manual can give you a direction for diagnosing a charging problem. Download one here: MyMopar - Mopar Forums & Information - Service Manuals

 

[Gerald Morris]

See if you can get another starter + solenoid, which is how they're made for all these old boats. Rock Auto sells some re-manufactured ones cheap enough. Replace what you have. With a recharged battery, try starting and running a bit. I suspect you will have no further trouble. Oh yes,

GET A BIGGER BATTERY!!!!

540 CA is WEAK bro! Going too cheap will cause you more headaches than spending just a few dollars (or kronen) more. I got a 900 CCA Exide battery for just $140, U.$.A. at Home Depot. My OLD battery, only replaced about 1 yr ago, was a good 800 CCA Mopar battery which was only 3 yrs beyond its end of life date.

Good batteries are WELL worth the modest investment.

If by chance replacing the solenoid/starter unit DOESN'T fix matters, then look for a dead short running from the #10 AWG black wire or red wire maybe running through your firewall, to the ammmeter. Do you still HAVE THAT source of grief? If so, bypass it. THAT would be my second most likely culprit for symptoms such as you describe.

I don't expect you will need to do the second step though. Your starter is by far the most likely source of this sort of problem. Had a Ford which did this just 40 yrs ago. It even smoked some jumper cables when that solenoid stuck.....

 

[Nicholas Gromak]

Here is a simple test. Put a voltmeter on the battery terminals and increase the throttle. Does the voltage increase? When I bought my '67 Newport I had a mechanic come with me to check the condition of the car before I bought it. When he got to the battery, he showed me that the alternator wasn't charging (with the car running of course). He showed me 11.3 volts on the meter.

After he gave his O.K. for everything else, I asked the seller if he would swap the alternator for the new spare he had in the trunk. The seller agreed and brought it to his mechanic which replaced the alternator and to everyone's surprise, the new one wasn't charging either!

Long story short, the seller's mechanic discovered that if you increase the throttle a bit, the alternator jumps to 14.6v at ~900 rpm. Even simple things can be overlooked. This would eliminate the alternator as a cause of the problem. As for the battery, I don't know much about CA or anything. All I can say is that I have a huge AC Delco battery from 2014 in my Chrysler and I left the lights on all night recently and it still managed to start the 383 (6.3L) V8 to get to work the next morning.

At least I hope my story was of some amusement to you and greetings from Canada! Good luck!

 

[Gerald Morris]

Here is a simple test. Put a voltmeter on the battery terminals and increase the throttle. Does the voltage increase? When I bought my '67 Newport I had a mechanic come with me to check the condition of the car before I bought it. When he got to the battery, he showed me that the alternator wasn't charging (with the car running of course). He showed me 11.3 volts on the meter.

After he gave his O.K. for everything else, I asked the seller if he would swap the alternator for the new spare he had in the trunk. The seller agreed and brought it to his mechanic which replaced the alternator and to everyone's surprise, the new one wasn't charging either!

Long story short, the seller's mechanic discovered that if you increase the throttle a bit, the alternator jumps to 14.6v at ~900 rpm. Even simple things can be overlooked. This would eliminate the alternator as a cause of the problem. As for the battery, I don't know much about CA or anything. All I can say is that I have a huge AC Delco battery from 2014 in my Chrysler and I left the lights on all night recently and it still managed to start the 383 (6.3L) V8 to get to work the next morning.

At least I hope my story was of some amusement to you and greetings from Canada! Good luck!

Stock Mopar alternators, especially the roundbacks, are NOTORIOUS for NOT charging at LOW RPM! Your story serves as a nice anecdotal underline to this basic truth, AND my advise w.r.t. battery size. My big Exide w its 900 CCA has yet to go dead on me, and I won't expect it for another 2 years, unless I pull something even more bone-headed than my former worst negligence. I have a 5 W 12V solar panel in the back under the rear window which charges the battery nicely even when left sitting for days. (Not that I can afford such luxury!)

 

[65sporty]

Go back to the beginning and start over. Charge the battery and test like Big John said. Get a wiring diagram and test the wires at the regulator and alternator like Dave said. Add a ground from the regulator bolt to the engine like 70 Fury said. If everything tests ok to this point, start the engine, let it run and watch the voltage. If you loose voltage at the battery, retest the voltage at the regulator and the alternator. This should help you find the problem.
This will help also
Mopar Charging System - MyMopar.com

This video shows how to test the alternator, but it will full field the alternator so don't leave the wire on long.
how to test mopar alternator with external regulators - Bing video

IMHO you don't need a starter, get the charging system straighten out and you should be on your way. Happy testing.

 

[Davea Lux]

In answer to the question "will anything fry a voltage regulator?" They will get fried instantly if a battery cable is unhooked with the engine running. They also will get fried if the case to the regulator is not properly grounded. If that has happened, it is fairly easy to spot. Unbolt the regulator and look at the backside of it. If a bad ground has fried it there will be a black burned spot and the regulator is toast. Be sure to correct the grounding issue when installing a new one.

Dave

 

[AztorTheSailor]

So this evening me and uncle (who is an electrician and quite good with engines) installed a new alternator, regulator and a brand new and more powerfull battery (74 Ah 680 A).
A small video after running a test for 6-7 minutes:



We belive now that the last alternator that was installed, went to hot and destroyed the diodes since the battery was not charged fully at all (and been flat twice before the new alternator came in).
The main reason this all started, was that the 3 days I drove the car this summer, it was a extremely hot weather, and I was driving for 2-3 hours each day. I think that is the reason the diodes on the original alternator started to go bad.
Will take the car for a drive tomorrow when it is daylight, gonna drive to my uncles company where he will go over it again with the voltmeter. Autuum/early winter here now so the hot weather has gone away for this year.

I would like to say thank you so much to all of you who took the time to answer me here and come with suggestions, links and pictures. I really like this forum alot. You are the best!

----
Here is a small film I made when I was driving over the Atlantic Road before the trouble started.

 

[Davea Lux]

So this evening me and uncle (who is an electrician and quite good with engines) installed a new alternator, regulator and a brand new and more powerfull battery (74 Ah 680 A).
A small video after running a test for 6-7 minutes:



We belive now that the last alternator that was installed, went to hot and destroyed the diodes since the battery was not charged fully at all (and been flat twice before the new alternator came in).
The main reason this all started, was that the 3 days I drove the car this summer, it was a extremely hot weather, and I was driving for 2-3 hours each day. I think that is the reason the diodes on the original alternator started to go bad.
Will take the car for a drive tomorrow when it is daylight, gonna drive to my uncles company where he will go over it again with the voltmeter. Autuum/early winter here now so the hot weather has gone away for this year.

I would like to say thank you so much to all of you who took the time to answer me here and come with suggestions, links and pictures. I really like this forum alot. You are the best!

Most of the time diodes will not get fried from charging a low battery. The quality of many of today's rebuilt alternators is very poor, folks rebuild them by replacing only the part that failed and leave all the rest of the old junk in the alternator. If they replaced one diode and the rest were at the point of failure, guess what happens next. That is probably what happened to you rebuilt unit.

Dave

 

[AztorTheSailor]

Most of the time diodes will not get fried from charging a low battery. The quality of many of today's rebuilt alternators is very poor, folks rebuild them by replacing only the part that failed and leave all the rest of the old junk in the alternator. If they replaced one diode and the rest were at the point of failure, guess what happens next. That is probably what happened to you rebuilt unit.

Dave

Yes you have a good point there. I will order new diodes and repair the two leftover alternators I now have.
Until next time things get to hot.

 

[65sporty]

As long as the voltage doesn't get any higher than 15.5v you should be ok, I prefer to see it closer to 14.8v, but that is all in the regulator.