71 charger 383 ammeter bypass?

[72RoadrunnerGTX]

So much mis-information in this thread relating to ammeters and not sure why it is posted to the fuel system section. These passenger car ammeters from this time period do not spontaneously combust. The ammeter connections will fail if not properly maintained or serviced. On a running healthy correctly wired electrical system in these cars, the ammeter only sees/shows the charge/discharge current flow as determined by the batteries charge state, it will not see full vehicle loads when running.

There are many threads in the electrical section where several users, dating back years, have attempted to counter the myth of the “dangerous” Mopar ammeter. Do some more research on the subject before hacking up your electrical system.

 

[Triple Black 73]

So much mis-information in this thread relating to ammeters and not sure why it is posted to the fuel system section. These passenger car ammeters from this time period do not spontaneous combust. On a running healthy correctly wired electrical system in these cars, the ammeter only sees/shows the charge/discharge current flow as determined by the batteries charge state, it will not see full vehicle loads when running.

There are several threads in the electrical section where several users, dating back years, have attempted to counter the myth of the “dangerous” Mopar ammeter. Do some more research on the subject before hacking up your electrical system.

Says the person that never had one burn up on them.

Mine was losing 2 volts and making a lot of heat just last year. I put way to much work into the car for an useless meter to burn my car up.

I wouldn't call it hacking up if you understand what it is and what the design flaw was. I would call it fixing a 45 year old factory engineer mistake.

 

[zsn0w]

It all worked fine when it was new. That's not an "engineering mistake", that's a system wearing out over time or not being maintained. This is why I have two lines, one through the ammeter and one bypassing it. The ammeter will still tell me if there is some massive discharge, but it's never going to burn because if it's suddenly a huge resistance, the current is just all going to take the other path. A cool idea would be to put a high current relay on the bypass line in this setup that is only on when the car is running. This would let you force the current through the ammeter when you have the key turned to ignition so you can see how much of a drain anything you have turned on is somewhat more accurately.

 

[Triple Black 73]

The ammeter measure the flow of amps from the generator/alternator (C) or from the battery (D). It was useful in the days of generators that couldn't handle putting out an constant current.

It all worked fine when it was new. That's not an "engineering mistake", that's a system wearing out over time or not being maintained. This is why I have two lines, one through the ammeter and one bypassing it. The ammeter will still tell me if there is some massive discharge, but it's never going to burn because if it's suddenly a huge resistance, the current is just all going to take the other path. A cool idea would be to put a high current relay on the bypass line in this setup that is only on when the car is running. This would let you force the current through the ammeter when you have the key turned to ignition so you can see how much of a drain anything you have turned on is somewhat more accurately.

It was a mistake because it was left over from the days of generators that could burn up when they over charged the battery. Chrysler even knew it was an issue, which is why they bypassed the meter completely with 60 or 100 amp alternators. So much for the "hack your harness theory".

 

[72RoadrunnerGTX]

Says the person that never had one burn up on them.

Got that right, none of the Mopar’s I own, or have owned, or have worked on, a rather large number frankly, have ever had an issue with their ammeters or their connections and never will while under my control. But then I’ve been working on these cars since the seventies, I know how to correctly maintain the connections and insulators at the ammeter.
As well, I have never blindly attempted to add heavy additional electrical loads directly to the battery on these cars. As I know that would cause higher than the design limit current across the ammeter and associated wiring. May even get hot and burn something. Is that the fault of the design?



“understand what it is and what the design flaw was”
My professional experience at the dealers back in the day also confirms the real design issue with the stock charging system was, first and foremost, the use of Packard 56 terminals in the charging circuit at the bullhead connector. And some Molex quick connects in the charge circuit in the engine harness on some models.

Ammeter useless? Couldn’t disagree more, voltmeters are as useless as idiot lights IMHO.

 

[zsn0w]

The ammeter measure the flow of amps from the generator/alternator (C) or from the battery (D). It was useful in the days of generators that couldn't handle putting out an constant current.


It was a mistake because it was left over from the days of generators that could burn up when they over charged the battery. Chrysler even knew it was an issue, which is why they bypassed the meter completely with 60 or 100 amp alternators. So much for the "hack your harness theory".

View attachment 814524

I believe that had much more to do with the connection at the firewall than the ammeter. The connectors there are the real weak point of the electrical system from what I've seen and heard. If the ammeter is connected tight it shouldn't ever be a problem, and I believe most of the cars that were fitted with the 60 or 100 amp alts at that point were fleet cars, which means they'd likely be sitting there for long periods of time without driving, draining the battery and causing a situation where a lot of current has to cross over the ammeter - a situation that normally never happens because it only shows drain or charge, i.e. too much on for the alternator to handle on its own like it should.

 

[Triple Black 73]

Got that right, none of Mopar’s own, or have owned, or worked on, a rather large number frankly, have ever had an issue with their ammeters or their connections. But then I’ve been working on these cars since the seventies, I know how to correctly maintain the connections and insulators at the ammeter.

“understand what it is and what the design flaw was”
My professional experience at the dealers back in the day also confirms the real design issue with the stock charging system was, first and foremost, the use of Packard 56 terminals in the charging circuit at the bullhead connector. And some Molex quick connects in the charge circuit in the engine harness on some models.

Ammeter useless? Couldn’t disagree more, idiot lights and voltmeters are useless IMHO.

Dude. Even the factory said to by-pass it with a 60 amp or 100 amp alternator way back in '73. You're as wrong as an ammeter is useless.

 

[72RoadrunnerGTX]

Chrysler even knew it was an issue, which is why they bypassed the meter completely with 60 or 100 amp alternators.

View attachment 814524

That is a mis-interpretation of the notations on that diagram. Need to follow up with the corresponding accessory diagrams when seeing those notations. Chrysler did not by-pass the ammeter on their taxi and fleet production large alternator vehicles, they by-passed the bulkhead connections with a separate harness/wires, still used an ammeter, on some models well into the eighties. The primary driving force for the move away from the ammeter was production cost, no other reason. The failed attempt to build them with plastic frames in the later trucks didn’t help.

Factory bulkhead connector by-pass

Ammeters in any DC circuit provide much real time diagnostic info.

 

[Triple Black 73]

I believe that had much more to do with the connection at the firewall than the ammeter. The connectors there are the real weak point of the electrical system from what I've seen and heard. If the ammeter is connected tight it shouldn't ever be a problem, and I believe most of the cars that were fitted with the 60 or 100 amp alts at that point were fleet cars, which means they'd likely be sitting there for long periods of time without driving, draining the battery and causing a situation where a lot of current has to cross over the ammeter - a situation that normally never happens because it only shows drain or charge, i.e. too much on for the alternator to handle on its own like it should.

No, the issue comes with folk started putting 60 amps alternator in the car. Which is why the factory by-passed it.

Look, the Type 59 connectors are only rated for 30 amps. Factory used a 12 awg feed wire. It's only rated for 30 amp. The ammeter is only rated for 30 amps. Deep C on the gauge is 30 amps. And guess what happens when you pump 60 amps through it? Everything burns up!

This makes me laugh to think the old alternator feed wire is now the ground wire for my fuel pump.

 

[Triple Black 73]

That is a mis-interpretation of the notations on the diagram. Chrysler did not by-pass the ammeter on their taxi and fleet production large alternator vehicles, they by-passed the bulkhead connections with a separate harness/wires, still used an ammeter, on some models well into the eighties. The primary driving force for the move away from the ammeter was production cost, no other reason. The attempt to build them with plastic frames in the trucks didn’t help.

Ammeters in any DC circuit provide much real time diagnostic info.

Yes, it's only good to make sure undersized wiring doesn't burn up!

 

[zsn0w]

No, the issue comes with folk started putting 60 amps alternator in the car. Which is why the factory by-passed it.

Look, the Type 59 connectors are only rated for 30 amps. Factory used a 12 awg feed wire. It's only rated for 30 amp. The ammeter is only rated for 30 amps. Deep C on the gauge is 30 amps. And guess what happens when you pump 60 amps through it? Everything burns up!

This makes me laugh to think the old alternator feed wire is now the ground wire for my fuel pump.

Unless something is wrong with your system, you're not going to have much amperage going through the ammeter at all. It ONLY sees current when the battery is being charged or the alternator can't keep up with electrical accessory load by itself. The source for electricity for all the accessories is on the alternator side, so you'd have to be constantly draining your battery to see a current across the ammeter constantly to power anything. If the battery needs to be charged, it will pull current across the ammeter from the alternator, which is the only other situation that the meter will have significant current going across it, and that's another example of a situation where something has gone wrong in your system beforehand.

 

[velrob]

Wow looks nice. I may do the same.

I plan to wire some relays also for my headlamp + electric fan so power doesnt go through the headlight switch so ill need some sort of bus bar as the lug only has 4 spots like yours.

The factory ran the 100 amp feed wire to the starter relay because it's the shortest and easiest path (about a 4 foot run). The issue is the alternator is on the right and the battery is on the left. The factory would either had go around the radiator (which is a 7 foot run), or across the firewall and down the fender, then back to the starter relay (which would be down right crazy). They could go over the engine, if the car had a small block, but a big block has the plug wire on the front which would cause all sort of issues if the feed wire was ran near them.

The ammeter measures the different of amps from the battery and what the alternator puts out. In my setup, I'm already at 90 amps with everything going and I plan to install three more fans (oil, p/s, and a pusher), along with a big car-audio system. If I had an working ammeter, that sucker would be pegged deep into the C zone and never move. So, it's 100% useless. In fact, the battery doesn't have enough juice for my car to run for more than a few seconds, a minute tops. It has just enough juice to spin the motor over before the alternator kicks in (it doesn't start working until it spins 1500 rpm which is why the pulley is so small). I monitor volts via the Sniper display screen.

I wasn't going to show my setup or talk about it much, because I think it's could be considered bragging, but I think it's relevant since you want to wire to the battery. On the right side, you'll notice the 4 awg cable ran off the alternator (it's cover in black Tech-Flex) going through the core support and a large service loop on the left of the car. The wire is tucked neatly under the core support. There is also a 4 awg ground for the alternator going directly to the frame. This is to insure a good ground for alternator, again to reduce AC whine. There's a new 4 awg cable to the starter, and 3x 10 awg running to the fuse/relay box inside the left front fender. The 8 awg to the starter relay is a little harder to see, but it's in there and ran off the battery in the bundle of smaller wires and then into the harness near the bottom of the battery. The two 4 awg ground cable is ran to the shut off, with a 4 awg to the engine and one to the frame. The ground bolts are carriage bolts, with two nuts. The alternator is the 220 amp PowerMaster with a March Performance 3-7/8 turn buckle reduced to 3-3/8. The end result of all this is a steady 14.1 to 14.3 volts with absolutely zero whine coming from the speakers.

View attachment 814253

Close up of the ground bolt. I have one on either side. The factory left a square hole on either side which I was able to fish a nickle plated steel carriage bolt through. Copper would have been better but my calculations showed this setup is good enough to meet my needs.

View attachment 814256

 

[zsn0w]

Wow looks nice. I may do the same.

I plan to wire some relays also for my headlamp + electric fan so power doesnt go through the headlight switch so ill need some sort of bus bar as the lug only has 4 spots like yours.

For that kind of stuff, you're going to want to run it on a line directly off the alternator stud. Put inline fuses or circuit breakers on the lines as close to the alternator as reasonably possible.

If I had an working ammeter, that sucker would be pegged deep into the C zone and never move. So, it's 100% useless.

Just read back over this in the quoted post above, I don't think you understand how the factory ammeter setup works. You should not be seeing a C unless the battery was drained and is being recharged. It doesn't make any sense for the ammeter to stay at C because it would mean that your setup has a constant battery-side drain. This would mean you have something with a high draw powered from the battery side of the ammeter in the charging circuit, which is the wrong way to set it up, not stock, and in most circumstances not very safe.

 

[velrob]

Alright ill run it off the alternator post.

What size fuses should i be using for the headlamps and electric fan?

For that kind of stuff, you're going to want to run it on a line directly off the alternator stud. Put inline fuses or circuit breakers on the lines as close to the alternator as reasonably possible.


Just read back over this in the quoted post above, I don't think you understand how the factory ammeter setup works. You should not be seeing a C unless the battery was drained and is being recharged. It doesn't make any sense for the ammeter to stay at C because it would mean that your setup has a constant battery-side drain. This would mean you have something with a high draw powered from the battery side of the ammeter in the charging circuit, which is the wrong way to set it up, not stock, and in most circumstances not very safe.

 

[zsn0w]

Alright ill run it off the alternator post.

What size fuses should i be using for the headlamps and electric fan?

I used a 15 amp for my low beams and another 15 amp for my high beams. I went with circuit breakers but fuses work just as well, it's just a preference thing (I like not having to worry about going under the hood to replace fuses if my lights wont come on). I bought a 30 amp for my electric fan setup, although I haven't gotten around to installing it yet. You might have to do some research on what fan you're using, but I'm planning on using one of the ford ones that are popular for retrofitting that can be found easily in a junkyard, and 30 is what most of my research told me is ideal.

 

[Triple Black 73]

Unless something is wrong with your system...

It's called corrosion, or a case of the green crusties. My old wiring was filled with it. The ammeter was filled with it. In a prefect world, with very low power usage, the ammeter would be fine. But with high output alternator having one is down right dangerous. I'm done talking about the stupid ammeter. And stop your bloody crusade to convince people it's an good idea to keep the ammeter before someone actually listens to you and their car goes up in flames, like mine did in '95.

Wow looks nice. I may do the same.

I plan to wire some relays also for my headlamp + electric fan so power doesnt go through the headlight switch so ill need some sort of bus bar as the lug only has 4 spots like yours.

I did the same thing to attempt to reduce the load on the old wiring as much as possible. The American Autometer Relay Panel I used is ground triggered, so I had to convert the headlight to ground trigger while keeping the high beam light working as it should. That was fun. Can't remember exactly what I did but the load is like 7 mili-amps now because I used an LED bulb for the high beam light.

 

[72RoadrunnerGTX]

But with high output alternator having one is down right dangerous. I'm done talking about the stupid ammeter.

That is a blatantly false and inaccurate statement. Clearly shows you do not fully understand the correct function of the ammeter and its place in the Chrysler charging system as it was originally designed. Alternator output capacity has nothing to do with the ammeter function on a correctly wired system. If the ammeter shows any charging, with a fully charged battery, then you have loads connected to the battery directly, on the battery side of the ammeter, that should not be there. Yes, that will in fact over stress the ammeter, its connections, and the charge circuit wiring well beyond its design limits. ALL vehicle loads need to be on the alternator side of the charging circuit when running an ammeter. There should be near zero current flow through the ammeter when the system is running. Ammeters in a healthy, correctly wired, system are NOT inherently dangerous. The danger comes from people servicing the system who do not fully understand the system or how to maintain it.

“bloody crusade”

I will continue to challenge false and mis-leading information posted here when and where I can. For the sake of others here trying to learn, you are welcome to post your opinions anytime, just don’t state it as fact.

 

[Triple Black 73]

That is blatantly false and inaccurate statement. Clearly shows you do not fully understand the correct function of the ammeter and its place in the Chrysler charging system as it was originally designed. Alternator output capacity has nothing to do with the ammeter function on a correctly wired system. If the ammeter shows any charging, with a fully charged battery, then you have loads on the battery side of the ammeter that should not be there. All vehicle loads need to be on the alternator side of the charging circuit when running an ammeter. There should be near zero current flow through the ammeter when the system is running. Ammeters in a healthy, correctly wired, system are NOT inherently dangerous. The danger comes people servicing the system who do not fully understand the system or how to maintain it.

“bloody crusade”

I will continue to challenge false and mis-leading information posted here when and where I can. For the sake of others here trying to learn here, you are welcome to post your opinions anytime, just don’t state it as fact.

Look. I said I was done. The point of this thread is not for you to get a soap box about how wonderful ammeter are. It is about helping Velrob upgrade his alternator to 105 amps and producing clean power.

That means running the alternator directly to the battery so that it will soak up the AC whine and then by passing the ammeter so it doesn't burn up.

 

[Nacho-RT74]

You can like the ammeter or not, that’s fine but you need to learn how works or what the readings mean. From that then check what is wrong with the system on your car and decide, but nobody can judge from the ignorance on how the system works. Even less tell to the rest THIS WRONG AND DOESN’T WORK from unknowledgement.

There is not a perfect system on anything but maybe the perfect for your needs

 

[zsn0w]

Look. I said I was done. The point of this thread is not for you to get a soap box about how wonderful ammeter are. It is about helping Velrob upgrade his alternator to 105 amps and producing clean power.

That means running the alternator directly to the battery so that it will soak up the AC whine and then by passing the ammeter so it doesn't burn up.

You say that you're done talking about it because the topic isn't why he should keep ammeter, it's why he shouldn't keep the ammeter??? You don't just get to portray your opinion as fact and then refuse to talk about the alternative... You don't understand how to ammeter works and should be set up. If you have actual reasons then fine, but what you're saying about the setup is downright wrong. If you have an adequate alternator and you have your system wired correctly, there should almost always be 0 current going across the ammeter. The setup you've described is wired incorrectly or has a short somewhere.