71 charger 383 ammeter bypass?

[velrob]

Hmm isn't the alternator always charging the battery ?

Id like to wire the ammeter so it does something. I will definitely go directly to the alternator for charging. If im using a bunch of relays then this would offload power going through the dash also. The only things that would draw most power is heater fan and wipers. All the bulbs I will be using inside will be LED. So power draw should be minimal going through the ammeter if any. My rear lamps and front will be off relays. Electric fan relay. Maybe I could wire the wiper off relay also?

 

[72RoadrunnerGTX]

Hmm isn't the alternator always charging the battery ?

When the battery reaches a full state of charge, it draws almost no current to maintain it and should register almost nothing on the ammeter, needle will be centered. If the ammeter shows a constant charge all the time, the battery has a problem, or more likely, there are added loads connected at the battery. These loads are drawing current from the alternator through the ammeter and charge circuit connections not designed for that current. The weak points are the bulkhead charge circuit terminals first then poorly maintained or loose ammeter connections. Any resistance will generate heat.

Id like to wire the ammeter so it does something. I will definitely go directly to the alternator for charging. If im using a bunch of relays then this would offload power going through the dash also. The only things that would draw most power is heater fan and wipers. All the bulbs I will be using inside will be LED. So power draw should be minimal going through the ammeter if any. My rear lamps and front will be off relays. Electric fan relay. Maybe I could wire the wiper off relay also?

As originally designed, all factory loads are on the alternator side of the ammeter and current flow for the loads will not be indicated on the ammeter when running. The ammeter only registers current to and from the battery as determined by the current battery state of change. If the alternator can’t keep up with vehicle loads for any reason, power is drawn from the battery and registers as a discharge.

 

[zsn0w]

Hmm isn't the alternator always charging the battery ?

Id like to wire the ammeter so it does something. I will definitely go directly to the alternator for charging. If im using a bunch of relays then this would offload power going through the dash also. The only things that would draw most power is heater fan and wipers. All the bulbs I will be using inside will be LED. So power draw should be minimal going through the ammeter if any. My rear lamps and front will be off relays. Electric fan relay. Maybe I could wire the wiper off relay also?

The way you want the system as a whole set up is nothing directly off the battery that wasn't there from the factory. So, you'll have the starter and that's pretty much it. Everything else should be wired up from the alternator side of the ammeter (it makes no difference if this is at the factory splice in the dash harness or directly off of the alternator stud). The battery only gets charged when it's been drained some previously, i.e. right after you start the car, if you left accessories on without the engine running, or if your alternator isn't powerful enough to supply adequate current to all of your accessories. The second and third of these situations will eventually drain your battery too low to start if left that way long enough and are fire hazards. The first is normal because the battery is being used to turn the starter motor since the alternator hasn't kicked on yet. This is why you can theoretically remove a battery once the car is on (not recommended) and it can still run.
The main thing you need to make sure of when adding any load to the system is that your alternator can provide enough current to power ALL of your accessories, lights, ignition, etc. - anything that needs power. And that's what the ammeter tells you. If it goes towards D when you have the car running and all accesories on, then your alternator can't keep up and your car is pulling current across the ammeter from the battery side to help out. If it's going towards the C, something is wrong with the battery or something is wired up on the battery-side of the ammeter that is using current from the alternator across the ammeter. Neither of these are good.
Now, I have a second line bypassing the ammeter on my car and another going through it. This is because I have no clue what the alternator that came on my car when I got it is. It's a roundback that I THINK is a 65 amp, but I'm not sure. Once I get the correct alternator for what I plan on running (around 100 amps) the bypass line won't be necessary. If you know what you're working with - and you know it's got enough juice to run what you have installed - and it is wired correctly, the ammeter doesn't cause any problems because it CAN'T. What will cause problems is the packard connectors at the firewall. Bypass those for sure.
You can wire almost anything off relays, but I wouldn't bother with things like the wipers. They are used infrequently enough and have a complicated enough switch that it isn't worth it. headlights, ignition, and - depending on the setup you run - electric fans should be run on relays for maximum efficiency.

 

[velrob]

Ahh all makes sense now. In this case using the ammeter wont be an issue for me. As long I keep an eye on my alt and battery. If drain is to high, shut off the car and see whats going on before a fire starts

I will be running the line directly bypassing the bulkhead to the ammeter. No Packard 59 connectors will be used or any connectors for that matter.

But I do see what you mean about bulkhead melting. Thats exactly what happened to the old terminal originally on the car. I was wondering why it was melted.

Now it makes sense. This is my first classic so i've learned alot.

 

[Triple Black 73]

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.

I understand perfectly well what an ammeter meter is, how it works, and how it should be setup. My grandfather was an electrical engineer. He help improve the original GM alternator by writing a letter to a GM engineer about the various flaws. GM went with his recommendation and improved the design. He was offer $50k to move to New Zealand in 1959. He spent many hours teaching me about electrical system when he was still alive. I soaked it up like a sponge. You should see the single to three phase converter we built together to run his milling machine. I wanted to go into electrical engineering, but went into computers instead. Now I do it as a hobby. Anyways, I think I might know my stuff just a little more than some washed up service adviser.

The issue you and others are completely missing is the fact that the original function of the ammeter was to monitor a 1950 style 35 amp GENERATORS (produces DC power) which would burn up under high load; As in the copper wire would heat up, melt, burn up, catch fire, and burn the whole damn car to the ground.

Modern ALTERNATORS (produces AC power that then go through a rectifier to produce DC current) don't burn up like that. They either work or they don't. The diodes on the field coil burn out, but neither the field coil nor the armature are effected. You replace the diodes and you're back in business. You monitor an alternator output via volts. If you don't have enough volts, you know the alternator isn't putting out enough juice. Simple as that. You don't need a damn ammeter for that!

You and that other goof needs to answer what good is an ammeter with an alternator?! I tell you, ABSOLUTELY ZERO. It's just ticking time bomb waiting to go up in smoke. The design of the system produces an ugly AC feed on the current. Go ahead, break out your oscilloscope take a look at the current. I'm sure a smart guy like you have one, right? Oh, you don't? I'm shocked!

The big issue here is that the ammeter is only rated for 35 amps. If the rest of your wiring is up to par, and you send more than 35 amps through it, guess what happens to the silly *** ammeter? Well you get a repeat of what happened to me in 1995: the damn thing burns up and parks your dumbass (for still having ammeter with an alternator) on the side of the road.

Like I said before. I'm done talking about stupid ammeters. Run one if you dare. Don't cry to mommy when it burns your car to the ground when you connect a 105 amp alternator to it. IDGF.

 

[Triple Black 73]

Ahh all makes sense now. In this case using the ammeter wont be an issue for me. As long I keep an eye on my alt and battery. If drain is to high, shut off the car and see whats going on before a fire starts

I will be running the line directly bypassing the bulkhead to the ammeter. No Packard 59 connectors will be used or any connectors for that matter.

But I do see what you mean about bulkhead melting. Thats exactly what happened to the old terminal originally on the car. I was wondering why it was melted.

Now it makes sense. This is my first classic so i've learned alot.

Dude. You're hooking a 105 amps alternator to a device rated for 35 amps. That's a disaster waiting to happen!

Wire the alternator directly to the battery like a modern day car, then run a 8 awg to the starter relay, bypass the ammeter completely. You don't need it with an alternator. It was only needed for a generator.

The type 59 connector is rated for 30 amps. If you run the headlights off relays, the rest of the old car system won't pull much current.

 

[Triple Black 73]

The way you want the system as a whole set up is nothing directly off the battery that wasn't there from the factory. So, you'll have the starter and that's pretty much it. Everything else should be wired up from the alternator side of the ammeter (it makes no difference if this is at the factory splice in the dash harness or directly off of the alternator stud). The battery only gets charged when it's been drained some previously, i.e. right after you start the car, if you left accessories on without the engine running, or if your alternator isn't powerful enough to supply adequate current to all of your accessories. The second and third of these situations will eventually drain your battery too low to start if left that way long enough and are fire hazards. The first is normal because the battery is being used to turn the starter motor since the alternator hasn't kicked on yet. This is why you can theoretically remove a battery once the car is on (not recommended) and it can still run.
The main thing you need to make sure of when adding any load to the system is that your alternator can provide enough current to power ALL of your accessories, lights, ignition, etc. - anything that needs power. And that's what the ammeter tells you. If it goes towards D when you have the car running and all accesories on, then your alternator can't keep up and your car is pulling current across the ammeter from the battery side to help out. If it's going towards the C, something is wrong with the battery or something is wired up on the battery-side of the ammeter that is using current from the alternator across the ammeter. Neither of these are good.
Now, I have a second line bypassing the ammeter on my car and another going through it. This is because I have no clue what the alternator that came on my car when I got it is. It's a roundback that I THINK is a 65 amp, but I'm not sure. Once I get the correct alternator for what I plan on running (around 100 amps) the bypass line won't be necessary. If you know what you're working with - and you know it's got enough juice to run what you have installed - and it is wired correctly, the ammeter doesn't cause any problems because it CAN'T. What will cause problems is the packard connectors at the firewall. Bypass those for sure.
You can wire almost anything off relays, but I wouldn't bother with things like the wipers. They are used infrequently enough and have a complicated enough switch that it isn't worth it. headlights, ignition, and - depending on the setup you run - electric fans should be run on relays for maximum efficiency.

You do realize that wiring like this means everything must be on the feed side: headlight relay, electric fan relays, car audio, ignition, EFI, ECU, FUEL pump. Everything. It all need to be on the feed side, and you get that wonderful AC whine.

Makes me ask, why even add a 105 amp alternator? Why not just keep the small 35 amp generator so you can monitor it with your ammeter?

 

[Triple Black 73]

When the battery reaches a full state of charge, it draws almost no current to maintain it and should register almost nothing on the ammeter, needle will be centered. If the ammeter shows a constant charge all the time, the battery has a problem, or more likely, there are added loads connected at the battery. These loads are drawing current from the alternator through the ammeter and charge circuit connections not designed for that current. The weak points are the bulkhead charge circuit terminals first then poorly maintained or loose ammeter connections. Any resistance will generate heat.



As originally designed, all factory loads are on the alternator side of the ammeter and current flow for the loads will not be indicated on the ammeter when running. The ammeter only registers current to and from the battery as determined by the current battery state of change. If the alternator can’t keep up with vehicle loads for any reason, power is drawn from the battery and registers as a discharge.

You're a damn fool, 72RoadrunnerGTX. An alternator puts out 14 to 14.4 volts where a battery can only handle 12.8 to 13.4 volts. If you have an unequal volts on one side you'll have current flowing to the other side to equalize the current. The rest of the current (which isn't much) is lost in the system. That's how the output of an generator is monitor via an ammeter.

If you were correct (which you are not), there would be will zero movement on the ammeter when turning on the headlights, thus zero monitoring of the output of the generator, so what the point of having one if not to monitor the output of the generator! It's not to monitor the charge of the battery! It's to monitor the output of the generator!

 

[72RoadrunnerGTX]

You're a damn fool, 72RoadrunnerGTX.....

What’s with the name calling? I assume you are addressing me, now I know you are, since I’m the only other one posting here countering your repeated bull-**** miss-information. Goof? Washed-up service advisor? Now, a damn fool? I never said I wrote service. I’m a washed-up ASE, Chrysler, Porsche, Mercedes certified master tech, high-end auto-sound store owner/design engineer/installer, IT consultant, network engineer. Only about 45 years’ experience however. Oh, also raised in a household headed by a Professional Electrical Engineer.

I know you said you were done talking about ammeters, but answer me this, if you understand how the system works, why do you keep associating a perceived ammeter ratting (which doesn’t exist) with alternator output capacity? There is no relation. Again, as designed, the ammeter will only see battery charging/discharging current, nothing to do with added loads or alternator output capacity. If the ammeter sees the anything close to the 35 amps you have described, you have loads added to your battery period and likely things will burn.

It's not to monitor the charge of the battery! It's to monitor the output of the generator!

Dead wrong.
No generator involved here, the ammeter is in series with the battery on one side and the alternator output and loads on the other side. Pretty simple really, nothing to do with alternator output.

 

[velrob]

Yikes didn't mean to start ww3 lol

 

[zsn0w]

I understand perfectly well what an ammeter meter is, how it works, and how it should be setup. My grandfather was an electrical engineer. He help improve the original GM alternator by writing a letter to a GM engineer about the various flaws. GM went with his recommendation and improved the design. He was offer $50k to move to New Zealand in 1959. He spent many hours teaching me about electrical system when he was still alive. I soaked it up like a sponge. You should see the single to three phase converter we built together to run his milling machine. I wanted to go into electrical engineering, but went into computers instead. Now I do it as a hobby. Anyways, I think I might know my stuff just a little more than some washed up service adviser.

The issue you and others are completely missing is the fact that the original function of the ammeter was to monitor a 1950 style 35 amp GENERATORS (produces DC power) which would burn up under high load; As in the copper wire would heat up, melt, burn up, catch fire, and burn the whole damn car to the ground.

Modern ALTERNATORS (produces AC power that then go through a rectifier to produce DC current) don't burn up like that. They either work or they don't. The diodes on the field coil burn out, but neither the field coil nor the armature are effected. You replace the diodes and you're back in business. You monitor an alternator output via volts. If you don't have enough volts, you know the alternator isn't putting out enough juice. Simple as that. You don't need a damn ammeter for that!

You and that other goof needs to answer what good is an ammeter with an alternator?! I tell you, ABSOLUTELY ZERO. It's just ticking time bomb waiting to go up in smoke. The design of the system produces an ugly AC feed on the current. Go ahead, break out your oscilloscope take a look at the current. I'm sure a smart guy like you have one, right? Oh, you don't? I'm shocked!

The big issue here is that the ammeter is only rated for 35 amps. If the rest of your wiring is up to par, and you send more than 35 amps through it, guess what happens to the silly *** ammeter? Well you get a repeat of what happened to me in 1995: the damn thing burns up and parks your dumbass (for still having ammeter with an alternator) on the side of the road.

Like I said before. I'm done talking about stupid ammeters. Run one if you dare. Don't cry to mommy when it burns your car to the ground when you connect a 105 amp alternator to it. IDGF.

You can have a debate without being an asshole man... No need for the name calling. You are completely wrong on a lot of this stuff, though... to have 35 amps running through your ammeter would mean a very, very under-powered alternator or a very discharged battery. The ammeter measures whether you are charging or discharging the battery. It will show if you have a slow drain somewhere or a short. Look at stock how the systems are wired up. If you think about it as inputs and outputs to/from the system, there is one input from the alternator and one input from the battery. The battery input goes through the ammeter to show you if it is being drained or charged, because unlike the alternator, you need that battery to stay charged if you want to restart the car after it's shut off. The output goes to all the electrical systems in the car. There is a splice in the harness on the alternator side that sends this output to all the different places it needs to go. I'm sorry your car got burnt in 1995, but maybe you should stop pointing the finger at the ammeter without understanding it...

You're a damn fool, 72RoadrunnerGTX. An alternator puts out 14 to 14.4 volts where a battery can only handle 12.8 to 13.4 volts. If you have an unequal volts on one side you'll have current flowing to the other side to equalize the current. The rest of the current (which isn't much) is lost in the system. That's how the output of an generator is monitor via an ammeter.

If you were correct (which you are not), there would be will zero movement on the ammeter when turning on the headlights, thus zero monitoring of the output of the generator, so what the point of having one if not to monitor the output of the generator! It's not to monitor the charge of the battery! It's to monitor the output of the generator!

The voltage from the alternator is regulated... Your understanding of electricity seems a little off here. If the battery is full, nothing is getting sent to it to charge it. There's nothing to charge. And if everything is run off of the alternator side, as the cars came from the factory and as they should be for safety and function, then nothing notable is running back through the ammeter to the battery side, certainly anywhere near the 35 amp limit you claim for the ammeter.

You do realize that wiring like this means everything must be on the feed side: headlight relay, electric fan relays, car audio, ignition, EFI, ECU, FUEL pump. Everything. It all need to be on the feed side, and you get that wonderful AC whine.

Makes me ask, why even add a 105 amp alternator? Why not just keep the small 35 amp generator so you can monitor it with your ammeter?

The higher powered alternator is because, as I've stated three times now, if you have a powerful enough alternator, you don't need to worry about large amperage over the ammeter. If you are seeing high draw from the battery side while running - which would happen with my setup and a 35 amp alternator because there's not enough amperage from the alt for the accessories - then the rest of the amps the accessories need are being pulled across the ammeter from the battery, and the battery is going to die.
I don't see the problem with this "AC whine" you are talking about.

 

[72RoadrunnerGTX]

It's not to monitor the charge of the battery! It's to monitor the output of the generator!

Ok, time to go back to school, jump ahead to 12:10 for the answer to today's question.

I suppose there is a small possibility all the Chrysler produced tech training materials could be wrong and Triple black is correct, but I don’t think so.

 

[Triple Black 73]

Ok, time to go back to school, jump ahead to 12:10 for the answer to today's question.

I suppose there is a small possibility all the Chrysler produced tech training materials could be wrong and Triple black is correct, but I don’t think so.

Fine. Let's me put it another way.

The ammeter answers the age old question can a weak 35 amp generator keep up with a weak 375 cca lead acid battery? Which is kinda important, because a 375 cca battery barely has enough to turn over an engine when fully charged, and a 35 amp alternator barely has enough juice to power headlights, the heater fan, radio, and power windows. God forbid all at once! If a generator gets overloaded, it burns up. If the battery discharged to much, it wouldn't start. So, the ammeter was very important back in the day.

Now, let's fast forward. Let's put in a 100 amp alternator with a 800 cca or 50 amp hour battery. But let's say the battery is 80% of capacity from just setting. That's still 660 CCA and 40 amp hours. Almost twice what the original design spec. That also means the outdated charging system needs to work over full capacity just to fill what was lost from just sitting! But 72RoadrunnerGTX says "there must be something really really wrong for that to happen". No man. Just a big battery at 80%. And that's enough to tax the '70s charging system to the point of self destruction.

Here's what's going to happen. There will be a huge voltage different between the alternator and the battery. The voltage regulator will see the lower voltage at the battery and direct the alternator to put out more power. It will do this until the volts on both end on equal (the battery is fully charged). However, the ammeter in our Chrysler is a "full load" design, so it will carry the full load. Since the voltage regulator will see the drop in voltage and not improving, it will tell the alternator to put out more and more and more amps to increase the volts. 20? 30? 40? 50? 60 amps? Boom. There's goes your car up in flames.

And it's exactly what I said all along. If I connected my 220 amp alternator through the ammeter to my 800 cca / 50 amp hour battery, the ammeter would be pegged deep into the 'C' and would stay there until it burned itself up.

The damn ammeter is an old design that has no place in today's world. If you upgrade the alternator or the amp or all anything to the system, bypass the ammeter. There's a reason no one car manufacture offers uses an ammeter to monitor charging levels. Modern systems puts the battery between the alternator and load to have it act like a capacitor to smooth out voltage spikes and AC whine.

72RoadrunnerGTX is seriously misleading people. He talks a good line, but present unimportant information as relevant. He glosses over the real important stuff. He doesn't use math or numbers to support his views. He want to apply old world tech in the new world. Not once has he admitted that the ammeter in Chrysler products are only useful in monitoring low amp system.

But if you guys wants to keep using them, you better keep using small alternators and small batteries.

 

[Triple Black 73]

I’m a washed-up ASE, Chrysler, Porsche, Mercedes certified master tech, high-end auto-sound store owner/design engineer/installer, IT consultant, network engineer. Only about 45 years’ experience however. Oh, also raised in a household headed by a Profession Electrical Engineer.

And yet, you can't see the problem with adding a big alternator into a system with full load ammeter designed 50 years ago for a weak generator and small battery?

 

[Triple Black 73]

Your understanding of electricity seems a little off here. If the battery is full, nothing is getting sent to it to charge it. There's nothing to charge.

Show me some math to support your claims. Use a '71 battery spec, then put in a modern battery. A battery is never 100% charged. There's always some capacity. And why has almost every single manufacture moved away from ammeter? 40 years ago!!!

I don't see the problem with this "AC whine" you are talking about.

I doubt you have anything modern enough in your classic to even notice. Me, I have a ECU and a high end audio system. Those systems need clean DC power. You don't get that with the way MaMopar built it.

Face the fact. The ammeter was designed for a weak alternator and small battery. This got started because someone wanted to add a large alternator to their system. I say by-pass the ammeter. You say keep it. Why? Hell I don't know why. All you keep saying is "oohhh. iT pERfecTlY sAfe!! DoN'T WorRY!" Well, my 1995 self would have liked to met you when my car was on fire. Asshole.

 

[zsn0w]

@Triple Black 73 Everything you are saying here is false. You are ignoring what we are saying. You very obviously do not understand what the ammeter does or how the charging systems worked in these cars, and you are name calling and making things up as a result... I seriously recommend anyone reading this goes and looks at this: http://www.dodgecharger.com/forum/index.php/topic,33574.0.html
I have explained my reasons multiple times but you don't seem too interested in reading them, so believe what you want. I'm sorry your car caught on fire, but it doesn't make me an asshole for pointing out that maybe your hate for ammeters in unjustified if you don't really understand how they work.

 

[72RoadrunnerGTX]

I take it you meant to direct this to Tripleblack?

 

[Triple Black 73]

@72RoadrunnerGTX Everything you are saying here is false. You are ignoring what we are saying. You very obviously do not understand what the ammeter does or how the charging systems worked in these cars, and you are name calling and making things up as a result... I seriously recommend anyone reading this goes and looks at this: http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

I know how it work perfectly well. You are ignoring the fact that this is not about the '70s charging system design.

This is about adding a big alternator to an old system that was never designed for it! Giving advice to add a 100amp alternator to something never design to handle it is dangerous.

 

[zsn0w]

I take it you meant to direct this to Tripleblack?

Yup my bad. fixed. Loaded up more posts mid typing and just copied and pasted

 

[Triple Black 73]

I shown you that a 800 cca battery, rated at 50 amp hours, which is a typical group 34 battery, at 80% full capacity is enough to overload the '70s charging system in these old cars.