Ammeter Quick Question and 95 AMP alternator question

[mrmolding]

In my 70 RR, I have all new harnesses, new OER gauges, except the rebuilt speedo from Redline (just wanted to plug the awesome work), and a new PowerMaster 95 AMP alternator, new NAPA battery, new Voltage Regulator and a Voltmeter that I added under the dash.

I actually like seeing the Ammeter since I grew up with one. I also know that Nacho has outlined an improved way to use an ammeter -- thinking about doing that.

So here is what I observe -- When I first start the car, the ammeter needle jumps to pegged right/positive but then settles down quickly and just slowly moves down to the 0 position and stays there.

What I think is happening -- I'm not an expert, but I think that the Voltage regulator is doing its job and bringing down the AMPs. I could be wrong, but I've read a few threads, and this seems to be what is happening.

Other things I've tried -- I do have a charge wire that I got from CrackedBack as part of his headlight harness. When I use the charge wire the ammeter of course just does not work but the concern goes away.
I've also tried a NOS 65-amp alternator I got from another member, but it squeaks, so I put the PowerMaster 95 AMP back.

Here is my question -- Do I need to be concerned about the initial high reading? Use a 100AMP shunt? Do Nacho's change so I can have the best of both worlds? Find a better older 46 AMP alternator?

Thoughts? In my day I was mainly a body/fabricator and mechanic's helper in my twenties so I'm slowly learning everything else.

 

[Don67Satellite]

Maybe you need to summon @Nacho-RT74 to weigh in.

Since this is always a lively debate.....

I also installed a nice new 95A alternator, but I still have 50yo wiring, so I have done the ammeter/bulkhead/underhood bypass' and run a voltmeter.

 

[Sinitro]

Talk to Shannon @ Red Line..
He recommends converting the amp gauge to a voltage meter. The original Mopar alternator in 70 was only 40 amps but if U upgrade to a 95 amp that will exceed was the amp gauge was designed to handle. Also be sure to clean and add dialectic grease to the bulkhead connectors.

Just my $0.02....

 

[mrmolding]

Talk to Shannon @ Red Line..
He recommends converting the amp gauge to a voltage meter. The original Mopar alternator in 70 was only 40 amps but if U upgrade to a 95 amp that will exceed was the amp gauge was designed to handle. Also be sure to clean and add dialectic grease to the bulkhead connectors.

Just my $0.02....

Thanks! I just want my ammeter and safely have it working. I met Shannon a few months back when he did my Speedo. I’m going to hold out until I can’t take it with the ammeter.

 

[mrmolding]

Maybe you need to summon @Nacho-RT74 to weigh in.

Since this is always a lively debate.....

I also installed a nice new 95A alternator, but I still have 50yo wiring, so I have done the ammeter/bulkhead/underhood bypass' and run a voltmeter.

Yeah. I mainly want to know if the initial surge on the gauge is a problem before I go full Nacho ammeter wiring fix. I’m pushing 60 and expect to see my gauge follow the turn signal blink at a stop. It’s part of the experience since that’s all we had back then.

 

[Sinitro]

OK..
Proceed @ your own risk...
Many Mopar dash fires are a result of overpowering the amp guage. Even though in most instances you seldom will use the full 95 amp alternator output but if the battery is run down forcing the voltage regulator to go max...
Also note the 0.25" tab terminals of the bulkhead connectors are a weak link.

Note that I am not trying to be a wise guy but our primary business is designing and building higher end custom car audio/video systems for SEMA and CES shows, just want to clarify certain points...

Just my $0.02..

 

[mrmolding]

OK..
Proceed @ your own risk...
Many Mopar dash fires are a result of overpowering the amp guage. Even though in most instances you seldom will use the full 95 amp alternator output but if the battery is run down forcing the voltage regulator to go max...
Also note the 0.25" tab terminals of the bulkhead connectors are a weak link.

Note that I am not trying to be a wise guy but our primary business is designing and building higher end custom car audio/video systems for SEMA and CES shows, just want to clarify certain points...

Just my $0.02..

Thanks! I understand those corner cases, just wondering if there is a sensible fix or concern beyond additional wiring. I'm really all about stock, stock, stock and enjoying the car as I remember them. If powermaster or tuffstuff made a new 46 amp alternator for guys like me instead of their 95 amp ones, there would not be a post. I've read so many posts here that I was happy thinking that even though it might be a higher amp alternator, it would never use that much so I'm fine. But when the car starts, the gauge pegs for a few seconds and therefore my concern.

 

[mrmolding]

Thanks everyone, the responses made me look for other types of answers and I found this at abodies. I think I'll try a 46 or do some type of mod. Thanks again everyone!
Which alternator 60A or 46A?

 

[Gold Rush]

I've been following this thread with interest and thus far haven't seen anyone really address the purpose of the alternator. It's there to recharge/keep the batter charged. Anytime the battery charge level drops the system voltage regulator senses that condition and supplies input to the alternator to output more current and voltage.

Out of curiosity, Have you checked the battery itself? From what I read your problem/concern is only after starting the engine. Unless you have to crank the engine for an excessive amount before it starts the starter should not drain a healthy battery charge to the point it needs massive amounts of recharge.

 

[mrmolding]

I've been following this thread with interest and thus far haven't seen anyone really address the purpose of the alternator. It's there to recharge/keep the batter charged. Anytime the battery charge level drops the system voltage regulator senses that condition and supplies input to the alternator to output more current and voltage.

Out of curiosity, Have you checked the battery itself? From what I read your problem/concern is only after starting the engine. Unless you have to crank the engine for an excessive amount before it starts the starter should not drain a healthy battery charge to the point it needs massive amounts of recharge.

Battery is fine from what I can tell. 12.6 volts after sitting a few days with my multimeter. Car starts like a champ in a crank or so unless it's been sitting and bowls have emptied. I think I'm starting to move on to Nacho's solution since 46 Amp roundbacks have one field connection from what I've seen after my last reply here. I upgraded to electronic ignition and it has two field connectors. Thanks!

 

[Nacho-RT74]

Again?

ammeter won‘t read anything unless battery got discharged or alt gets death or not sufficient. No matter if the alt is 500 amps, but the batt (while engine is running ) will stablish the load will suck up to be recharged and running through it. While batt keeps its load, which with a powerful alt will be pretty much the regular stage, ammeter won’t get any load running through and being on center.

sure is better get the power paths upgraded/fixed, but mostly to be sure the power will be spreaded all around safely. Including ammeter conditions after 50 years of abuse when times to get charge or discharge reading comes into the game.

your car will be still sucking the same load no matter the alternator and battery you put in. But with more capacity the power balance, where the power is spreader out (very important on cars with ammeters… source stuff from batt is a huge mistake on them ) and path conditions is important.

I don’t think more post from me are really needed to explain this, but just post old threads about this. And sure some red Xs will come on again and again from same members…I don’t care. My car can testify this after many years of real daily drive (REAL daily) use

 

[Nacho-RT74]

On a side note… you can try it just installing the alt and running the car for couple of days. If you are not satisfied with the new readings on ammeter, bypassing the system can be made anytime later after confirm what I’m saying is true or false. Of course based on a GOOD CONDITIONS wiring and stuff.

amd NOTHING being sourced from batt, not at least high load accesories ( no headlights relays or anything) because this will make to run the load through the ammeter like a CHARGE reading, where is not really charging but sourcing accesories. not a load really necessarilly to be running through the amm giving an unreal reading And stressing the gauge unnecessarilly

 

[dvw]

I bypassed the terminals in my Challengers firewall bulkhead. Just pulled the terminals and ran a solid piece of wire through. All the other wiring is factory. Been running a 110 amp alternator for 18 years.
Doug

 

[mrmolding]

On a side note… you can try it just installing the alt and running the car for couple of days. If you are not satisfied with the new readings on ammeter, bypassing the system can be made anytime later after confirm what I’m saying is true or false. Of course based on a GOOD CONDITIONS wiring and stuff.

amd NOTHING being sourced from batt, not at least high load accesories ( no headlights relays or anything) because this will make to run the load through the ammeter like a CHARGE reading, where is not really charging but sourcing accesories. not a load really necessarilly to be running through the amm giving an unreal reading And stressing the gauge unnecessarilly

Ok. That finally makes sense! I was VERY worried about starting another lengthy discussion.

My original question is: Do I need to be concerned that with the 95 AMP alternator, it pegs to the right for a few seconds and then comes down and stays at zero? Is that too much current (or whatever) going through the gauge and harness?

Everything in my car is new and stock in my case -- harnesses M&H, gauges OER, I even replaced all of the pigtails for lights and bulbs, even all fuses. Should be all stock and new. Just wondering if the initial high reading showing on the ammeter is a problem. After that it seems fine and basically sits at zero.

 

[Sinitro]

Keep in mind..
The purpose of a higher output alternator is to support a system that has many add-on devices that draw more current above the OE factory ones, such as a subwoofer system, electric fuel pump or electric fans. The highest current draw in vintage Mopar OE systems are the standard incandescent headlights which average around 20-25 amps, also a lot of stop and go driving prevents the system having a full charge. We have installed and wired multiple higher current Mopar electrical systems, and the worst case is when electric fans are installed as these can draw up to 40 amps..

Nuff said..

Just my $0.02..

 

[mrmolding]

Keep in mind..
The purpose of a higher output alternator is to support a system that has many add-on devices that draw more current above the OE factory ones, such as a subwoofer system, electric fuel pump or electric fans. The highest current draw in vintage Mopar OE systems are the standard incandescent headlights which average around 20-25 amps, also a lot of stop and go driving prevents the system having a full charge. We have installed and wired multiple higher current Mopar electrical systems, and the worst case is when electric fans are installed as these can draw up to 40 amps..

Nuff said..

Just my $0.02..

I understand all of that and I appreciate the info. My car is stock, stock, stock. If someone made a new 46 AMP alternator with two fields, there would not be a thread.

I am just trying to understand if I need to be concerned that my ammeter gauge jumps to the right using a 95 AMP alternator when my car starts and then slowly goes to zero. That's it. If it is concern, then I will figure something else out.

 

[mrmolding]

Keep in mind..
The purpose of a higher output alternator is to support a system that has many add-on devices that draw more current above the OE factory ones, such as a subwoofer system, electric fuel pump or electric fans. The highest current draw in vintage Mopar OE systems are the standard incandescent headlights which average around 20-25 amps, also a lot of stop and go driving prevents the system having a full charge. We have installed and wired multiple higher current Mopar electrical systems, and the worst case is when electric fans are installed as these can draw up to 40 amps..

Nuff said..

Just my $0.02..

So where is your shop? Looking for a decent place in SoCal since I'm swamped with my 73 RR.

 

[Sinitro]

We closed the shop last year..
Now semi-retired...
And doing product development and sourcing for multi-media, home theater and home automation components..

Just my $0.02...

 

[mrmolding]

We closed the shop last year..
Now semi-retired...
And doing product development and sourcing for multi-media, home theater and home automation components..

Just my $0.02...

Oh well! I need to get the 73 going under its own power or sell it since it's a roller in a small garage. Storage costs around here are nuts. Thanks!

 

[451Mopar]

The Amp gauge is not the main issue, it is the the packard 58 terminals at the bulkhead. I would not want to put more than 20 amps through one of those connections.
Next is the alternator wire size, I think it might be 10AWG in size.
I use the 4AWG powermaster alternator output wire direct to the battery positive (or at least the NSS battery connection.)
You can take the old alternator wire and add a fusible link to it and connect it to either the alternator output or the NSS stud, this will split the load with the original battery input through the bulkhead connector, but the amp gauge will just stay centered , because it is basically bypassed.