charger is overcharging? whats my issue?

[Stegs]

ok guys, I will give you the best background that I know about the car. The guy I bought it from went thru the entire car and made sure everything was working. Knowing that, here we go....

I bought the car wed. 6/18/14. I drove the car home, around the block, that night and the next day. No problems to worry about, the only thing I noticed was the amp gauge was discharging. I thought that it was the alternator..

so on fri 6/20 I take it to have the alternator tested. They started out testing the battery (which was 10 years old and had a bad cell) It was enough to start the car but I bought a new one. They tested the voltage regulator, said that wasn't working properly, so they put on a new one

After all this, the amp gauge still showed it was discharging. They said it was likely the alternator b/c the car sat so long, it was probably corroded. They told me to take it back this week and they will pull it of, and go thru it.

So fast forward to yesterday 6/25. They pull the alternator off, tear it down and see a few thing wrong, there was corrosion inside, so they cleaned it up, there was a bad bearing, so they replaced that....got it all done, tested it, works great!

They put it back into the car, start the car up to make sure everything is ok. Everything check out ok, battery is good, alternator is charging as needed.

Here is where it gets tricky, the car was running for 2-3 min while they were checking everything, and they started seeing the black ground wire that goes into the fuse block on the fire wall getting hot, and a little smoke.


They shut the car off right away, and go back to make sure everything was hooked up and a wire didn't vibrate loose. Everything checked out ok

they start the car back up, testing the voltage on the ground wire that got hot, and its 17.8-17.9 volts there. They shut the car off again b/c they determined the car is overcharging.

They unplug the alternator, so its disabled, (so the car is running of the battery alone) and the wire does not get hot, and everything else works (lights, blinkers, turn signals, etc)

They are lost at what it could be.

I get the car home (on the battery alone) and call the guy I bought it from. He is a huge mopar guy, owns 8+ cars, he went thru the entire car and made sure everything was ok before he sold it.

Everythign was and still is working fine, except the car wont charge, when we plug in the alternator it overcharges and gets the ground wire hot...


he (the guy I bought if from) came over last night to see if he could figure it out. He told me that its weird that a ground wire is getting hot, normally it would be a red, or yellow wire that carries juice that gets hot.


Anyway long story short, he thinks that the voltage regulator that they put on 6/18 is not for a big block car with a/c. He thinks when the alternator got fixed and started pumping juice thru the system, the voltage regulator failed, and that's whats causing this


Can anybody give me insight or your opinion. Im going today (6/26) to get a different regulator, something for a big block car with ac. Im going to put that on tonight and see what it does


When we were testing it last night, at idle the gauge in the dash said 0-10, but when you gave it gas it pegged out at 40, then it would slowly work its way down to about 20 idling, but at that point the wire was getting hot so we had to shut the car off.


Im not a automotive electric guy, I hate wires. Jim (who I bought it from) is pretty good and he thinks the regulator is bad, or the fuse block connection is bad.

I can take it to a local place near my house where they do stuff just like this, but at 80-100 dollars a hour, id hate to have it there for 3-6 hours, and they fix the problem in 10 min but I get charged for 4 hours "diagnose time"


Anybody run into this issue or similar issue?

FYI, ALL the "hot wires" on the car are just fine, its only the one ground into the fuse block that got hot.

HELP ME< I DONT WANT MY CAR TO BURN LOL

[myk]

Voltage regulators go bad all of the time-doesn't matter if it's used or new, especially if it's one of the "hecho en China" pieces.  Try another unit or maybe try the one that came with the car.  Keep in mind that assuming your alternator is functioning properly, it can't overcharge, as the voltage regulator dictates how much juice gets through the system; someone please correct me if I'm wrong.  As for your hot negative cable, the only thing I can suggest is that there's a lot of resistance in that cable, and resistance in an electrical path will generate heat.  Maybe check the terminal connection?  Check the cable for internal corrosion or breakage?

Oh, and if you don't want your car to burn down, I strongly recommend that you bypass your 'amp gauge; that's a trouble spot in the system even when these cars were newer and there's no way any of us can determine what shape your electrical system is in now, with almost 50 years on the clock.  Yes, there are those that love the 'amp gauge and there are modifications to safely run it, but....why bother IMO.

One last thing: if you're into cars you can't let the money part of it get to you-you have to pay to play...

[Ghoste]

Because how many do you actually know of that have burned down at the amp guage?  Especially when they were new?  It has far more to do with proper electrical system maintenance and overloading a system designed for a much lower power requirement with all these modern high draw components we insist we need.  (yes, I am one of those who is quite comfortable with his antique ammeter when its properly used)

[myk]

Because how many do you actually know of that have burned down at the amp guage?  Especially when they were new?  It has far more to do with proper electrical system maintenance and overloading a system designed for a much lower power requirement with all these modern high draw components we insist we need.  (yes, I am one of those who is quite comfortable with his antique ammeter when its properly used)

I don't know anyone actually.  I'll even wager that maybe it's never even happened in the history of Mopar-bilia.  But I love my car, and I'm willing to bet the 'OP does as well, so the logical step is to take the stand that he shouldn't take any chances with it.  Again, with almost 50 years of age and rot working against that wiring an old car owner needs to take as many safe guards as possible.  Even if the 'amp gauge fire has never happened in any Chrysler vehicle in the entire universe YET, I wouldn't want to be the first one that experiences it, and I'm sure the 'OP doesn't want that honor either.

BTW, if the 'amp gauge fire wasn't a potential problem why did Chrysler develop a work-around for it back in the day?

[Back N Black]

Myk, how do you monitor the charging system with the Amp gauge by-passed? are you using a volt gauge?

[W4ATL]

If the new voltage regulator is mechanical, it may be not be adjusted right. Open it up and you should see some adjustments on it to lower the voltage to the battery.

There is no ground wire that I know of to the fuse block so I'm not sure what you are talking about. The only Black wire I see to the fuse block is the Accessory feed from the key switch to the fuse block. That feeds the radio and fan motor. That's according to my '68 service manual.  Charging of the battery should not be going through the fuse block.

[1974dodgecharger]

Ammeter is fine it's when people need more juice is when it goes bad.  What all of sudden last ten years peoples ammeter burnt up but didn't burn up in 60s to 2000.  It's because people demand more juice such as msd, radio, etc...put in a bigger alternator without upgrade wires is when ammeter can't handle it.

I use a voltmeter I can tell if its not charger if my volt meter just sits at 12.5volts at driving means my regulator has died.

[myk]

Myk, how do you monitor the charging system with the Amp gauge by-passed? are you using a volt gauge?

Well....you can't really measure what the 'amp gauge measures with a volt gauge, right?  It's my understanding that all the volt gauge does is measure the state of the battery, which says nothing about the charging system.  I know that's short-sighted and risky but I don't want to deal with ammeter-I'm fine with the voltmeter.  But, like '74Charger said before me, if my voltmeter is only reading 12 volts or whatever then I know something is amiss...

[Ghoste]

I may be mistaken but I believe the back in the day "workaround" was designed for police and other emergency vehicles with increased power demands?
In any case, your concerns are valid Myk and its your car so you have to to do what makes you feel safe in it.  I just react I guess when I read all the posts on the internet about what horrible fire hazards Mopars are because they have an ammeter instead of a voltmeter.  It was never an issue until people started adding modern auto demands to old cars and many of which had wiring harnesses hacked up and customized beyond recognition.  It wasn't bad engineering on Chryslers part as its so often made out to be.
Its all good though.

[myk]

I may be mistaken but I believe the back in the day "workaround" was designed for police and other emergency vehicles with increased power demands?
In any case, your concerns are valid Myk and its your car so you have to to do what makes you feel safe in it.  I just react I guess when I read all the posts on the internet about what horrible fire hazards Mopars are because they have an ammeter instead of a voltmeter.  It was never an issue until people started adding modern auto demands to old cars and many of which had wiring harnesses hacked up and customized beyond recognition.  It wasn't bad engineering on Chryslers part as its so often made out to be.
Its all good though.

I've had some of the wiring melt and burn in the Charger while I was driving it and it was not a pleasant experience.  I may seem overly paranoid about a potential vehicle fire, but it is my hope that none of us ever has to experience what I did or something even worse...

[1974dodgecharger]

Like ghosts said its fine and nothing wrong with upgrading.....I say do it, I mean come on I have a 180amp idle and 320 amp at 1500 rpm output, lol.

[Pete in NH]

Stegs,

Welcome to the group and that's one really nice car you have there.

To answer some of your questions, First, there is no different voltage regulator for A/C or non A/C cars and engine size doesn't matter either. 1969 was the last year for the old electromechanical voltage regulator system and single field wire alternator. Many of these cars were converted to the newer 1970 and up electronic voltage regulator and duel field wire alternators. Look at the back of the alternator, if you have one heavy black wire and one lighter gauge green wire it is the older 69 system. If you have one heavy black wire and two other lighter gauge wires , it is a 70 and up system. If you can post pictures of the alternator and voltage regulator on the firewall it will help identify what is in the car. Frequently on 69's people get the alternator and regulator combination wrong. Once we know what type of system is in the car it's fairly easy to get it sorted out.

I suspect your problem is either a wrong or bad voltage regulator or open circuit in the charging circuit path. These are very simple systems but seem to cause no end of confusion for people today who are not used to 40 years old systems.

Ghoste, you have it absolutely right. These systems as designed are just fine and Chrysler did a good job on the engineering. They did push the bulk head connector pins a bit but, they knew it and that is why the 60 amp alternator cars got the bypass mod from the factory. My view is, trying to push the system beyond its design limits, modifications and 40 years of wear and tear causes the problems people have.

[Nacho-RT74]

damaged batt can cause that too.

another mistake usually made allong the years is upgrade batts with more powerfull ones keeping same alt and source extra added accesories from batt.

[Ghoste]

I put in a heavier than required battery once some years ago.  I didn't source anything extra to it but I did learn the hard way it was a bad thing to do.  It didn't cause a fire but it did overwork the charging system and contrary to my thinking when I did it, it actually shortened the life of the battery.  My thought of course was that a larger battery would make less work for everything.   It's a carefully balanced system not unlike a lot of other parts in a car.

[Stegs]

ok guys, some great info to look into

the car is stock, no aftermarket radio or lights, heck I don't even drive the car at night to use the headlights

here is what I got

the alternator when they rebuilt it was making 12.8v at 50 amps, this was 5 min before they put it back into the car

the alternator is not stock, but obviously it was rebuilt yesterday (6/25) to those specs

battery is new, it has 50 more cca than what was in...no big deal


New info, just got off the phone with the guy I bought it from, he says the black wire is suppose to be red, and its what comes from the alternator. It was more in the center of the fuse block, but he moved it to the lower right corner.

Its a little heavier wire than the rest, but that is the wire that got hot. I thought it was a ground, but its acutally a hot wire that comes (or goes) to the back of the alternator

I called the company that put the new regulator in and they said it tested out just fine

When I start the car, and give it gas till about 2000 rpms, it will peg out the amp gauge at 40+

I think the regulator they put on is bad, b./c I shouldn't have 40+ amps if it was working properly

either I have a bad regulator or I have a short, but the car had 0 issues before they switched parts around

hope that helps guys! little more info to go on

[firefighter3931]

If the battery is fully charged the ammeter should not be pegged on startup. When the regulator is functioning properly the ammeter will read near zero or the middle of the scale with a fully charged battery. 

Everything is pointing towards a defective voltage regulator 

I like to keep the idle up at 800rpm in gear. This keeps the alternator spinning fast enough to keep the battery from draining. Chrysler alternators are notorious for low amp output at slow engine speeds.

The other advantage to an 800rpm idle is critical lubrication to the cam & lifters. Those parts are splash lubricated off the rotating assembly and the more oil you can fling up there the better 


Ron

[Stegs]

at idle the car sits at about 6-8 on the gauge in the dash

If I bring it up to 2000 rpms or so, that gauge gets buried so fast to 40+ amps


the thing is I cant let the car run long enough to charge the battery to level....when I get home, im going to pull the battery cables off...put my battery tender on until its a full charge


during this time im going to check the wire that got hot and make sure the inside is ok. It should be since all the lights, turn signals work still, it didn't melt anything

Ill have to replace that wire, probably end up dropping the steering column in the car to make sure it didn't melt on the inside.

Im getting the feeling that old wires are going to kick my A$$!  

[Pete in NH]

Stegs,

Please go back and read my original post. If you're getting 17+ volts out from your alternator, it is running wide open and the regulator has no control. You have either a bad regulator, wrong regulator, open ground or a wiring problem or error.

If the alternator was rebuilt as a 69 alternator but the car has a 1970 or up regulator that is a problem. If the regulator is not connected to the alternator output through the ignition switch, that is a problem.

The black wire from the alternator output stud goes through a bulk head connector pin to one side of the ammeter, this same side of the ammeter is connected to what Chrysler called a "splice joint" and this point picks up all the electrical loads in the car. The other side of the ammeter goes through another bulk head connector pin, through a fusible link, to the 5/16" battery stud on the starter relay and on to the positive side of the battery. If the wiring between the alternator output stud and the ammeter is open you will see what you have happening now. Like I said, many of today's mechanics are not familiar with these ammeter systems and the duel /single field alternators on these old Mopars. This is why I was asking about the type of alternator and regulator in your car. I would not assume people working on your car know how it really works.

Don't run your car in this condition, you will damage your new battery. If you need to move the car, do it on the battery and disconnect the voltage regulator until this issue gets fixed.

[Stegs]

We picked up a new regulator ....I just pulled the old one off and it stuck touching....which to me means the power was flowing right thru it. We put a new regulator on but before we tried it I took apart the connection in the fuse block where it got hot........turns out it melted the bottom corner of the fuse block.....so now I have to go back and drop the steering column to get at the backside of the fuse block to make sure it didn't melt thru

I'm going to replace the wire from the inside all the way thru the fuse block.

Once I get all the wiring replaced I should be OK...new regulator and all new wire.