Diagnosis MOPAR Charging System

dadsbee said:

I do every day asshole, instead of belittling them!

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I’m here to learn and help others when I can

There’s always something new that can be learned.

A one-wire alternator bypasses everything and requires a volt meter because the factory ammeter cannot handle the current and would turn itself into a fuse and you’d be left without any electricity to run the vehicle once you shut off the engine.

Because the vehicle electric system is connected to the alternator side of the blown out ammeter, you won’t have any juice to re-engage the starter so you really need to do a major rework to the electrical system to get power back to the fuse box.

The simplest way is to move the wire on the battery side of the ammeter over to the other post and, thus, eliminate the ammeter but, now, there’s no way to measure the alternator output.

So, now, you need to install a voltmeter.

But, since everything goes through the bulkhead connection and that’s all corroded, you still have electrical gremlins that will require attention.

A one-wire alternator is just a patch and not a solution.

Fix the real problem and, unless you need the high output alternator to run non-standard cooling fans, stick with the wiring ChryCo designed for the vehicle.

The stock path is a trash can as designed from the start.

How you decide to fix it is up to you. Run the ammeter or not, pick your approach and do it wisely.

ynst said:

A one-wire alternator bypasses everything and requires a volt meter because the factory ammeter cannot handle the current and would turn itself into a fuse and you’d be left without any electricity to run the vehicle once you shut off the engine.

Because the vehicle electric system is connected to the alternator side of the blown out ammeter, you won’t have any juice to re-engage the starter so you really need to do a major rework to the electrical system to get power back to the fuse box.

The simplest way is to move the wire on the battery side of the ammeter over to the other post and, thus, eliminate the ammeter but, now, there’s no way to measure the alternator output.

So, now, you need to install a voltmeter.

But, since everything goes through the bulkhead connection and that’s all corroded, you still have electrical gremlins that will require attention.

A one-wire alternator is just a patch and not a solution.

Fix the real problem and, unless you need the high output alternator to run non-standard cooling fans, stick with the wiring ChryCo designed for the vehicle.

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Not following, what does a one-wire alternator have to do with the shunt wire bypass discussion here? Where would all the current come from that supposedly would kill (open) the ammeter when a one-wire alternator is installed? Ammeters are not measuring alternator output, should only be monitoring battery charge/discharge current, nothing to do with alternator output capacity.

Crackedback said:

The stock path is a trash can as designed from the start.

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And yet seemingly countless Chrysler products came and went running this same basic charging system for a couple of decades. The vast majority had no issues at all when left alone, well maintained, no misplaced loading, and otherwise operated within its design limits. It served its original purpose. No fibbing.

The one wire between the alternator and the battery is nothing but a shunt around the ammeter.

That’s why Powermaster says it’s just fine.

It ain’t “just fine”. It’s a work-around for keeping the battery charged but it does nothing to remedy bad bulkhead connections and those marginal connections in your bulkhead connectors are where the voltage goes INTO the fuse box, headlight switch, ignition switch, etc.

72RoadrunnerGTX said:

Not following, what does a one-wire alternator have to do with the shunt wire bypass discussion here? Where would all the current come from that supposedly would kill (open) the ammeter when a one-wire alternator is installed? Ammeters are not measuring alternator output, should only be monitoring battery charge/discharge current, nothing to do with alternator output capacity.

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If you connect a high output alternator to the factory wiring, you’ll blow out the ammeter so Powermaster bypasses the factory system with a shunt ( their one-wire) that STILL doesn’t address the real issue of bad firewall connections.

ynst said:

If you connect a high output alternator to the factory wiring, you’ll blow out the ammeter so Powermaster bypasses the factory system with a shunt ( their one-wire) that STILL doesn’t address the real issue of bad firewall connections.

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And THAT’S why they say that there’s nothing wrong with a shunt.

72RoadrunnerGTX said:

And yet seemingly countless Chrysler products came and went running this same basic charging system for a couple of decades. The vast majority had no issues at all when left alone, well maintained, no misplaced loading, and otherwise operated within its design limits. It served its original purpose. No fibbing.

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When left alone and well maintained…therein lies the problem that a lot of people have. 50+year old wiring harnesses with unknown corroded or partially broken wires coupled with aftermarket stereos, amplifiers, electric fans, fuel pumps, and the list goes on… The more loads placed on the factory system with a compromised (corroded) bulkhead connector or partially broken wires leads to higher resistance. Higher resistance leads to heat and heat is not good in this specific situation.

ynst said:

The one wire between the alternator and the battery is nothing but a shunt around the ammeter.

That’s why Powermaster says it’s just fine.

It ain’t “just fine”. It’s a work-around for keeping the battery charged but it does nothing to remedy bad bulkhead connections and those marginal connections in your bulkhead connectors are where the voltage goes INTO the fuse box, headlight switch, ignition switch, etc.

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OK, it appears you are referring to the discussed “shunt wire” bypass as a “one wire alternator bypass”? A bit confusing with a one-wire alternator. However, it not only bypasses the ammeter, it bypasses the entire stock charge path, disables the intended function of the ammeter, and most significantly, it circumvents the circuit protection for the entire stock unfused wiring, exposes all stock wiring to very high battery sourced current levels in the event of a short anywhere.

ynst said:

If you connect a high output alternator to the factory wiring, you’ll blow out the ammeter so Powermaster bypasses the factory system with a shunt ( their one-wire) that STILL doesn’t address the real issue of bad firewall connections.

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Just to be clear, simply swapping in a high output alternator in place of the stock rated alternator on an all-stock charging system, no changes to loading, isn’t going to blow out the ammeter. There will be no increase in current flowing through ammeter just because the alternator capacity increases.

The Powermaster alternator is a shunt system with a (recommended) fusible link.

It bypasses the factory charging system altogether, however, it does not eliminate the factory fusible link on the starter relay from where the power to the inside of the vehicle is derived so the factory protection is still there.

THIS is why Powermaster says that there's nothing wrong with a "shunt" wire. Theirs is a shunt system, therefore, there's no problem with a shunt. That's NOT the case in any situations except with their one-wire alternator systems.

This is also NOT the case with a ChryCo charging system, however UNLESS you make the a fore-mentioned modifications to the ammeter but it's only a patch to help maintain proper voltage levels at the battery.

If you try and bypass a factory MoPar alternator in the same fashion, the same original fusible link on the starter relay will protect the body harness but the alternator output will NOT be protected unless you add an additional fusible link in your shunt wire but that's still not going to cure your problem.

The reference voltage for your voltage regulator comes off the ignition circuit and if you have faulty bulkhead connections, that reference voltage will be incorrect and your charging system will STILL be screwed up.

The fix, as has been mentioned before, is to repair/replace the bulkhead connections, not a kludge shunt bypass, and THAT will solve your problems, .

72RoadrunnerGTX said:

Just to be clear, simply swapping in a high output alternator in place of the stock rated alternator on an all-stock charging system, no changes to loading, isn’t going to blow out the ammeter. There will be no increase in current flowing through ammeter just because the alternator capacity increases.

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UNLESS the battery's flat and the engine's running at high idle after start-up which will put the alternator output close to maximum as it tries to charge the dead battery. It WILL fry the factory ammeter.

ynst said:

UNLESS the battery's flat and the engine's running at high idle after start-up which will put the alternator output close to maximum as it tries to charge the dead battery. It WILL fry the factory ammeter.

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How much current do you believe will open one of these ammeters? If the battery is completely flat (discharged), how do you get it started?

ynst said:

The Powermaster alternator is a shunt system with a (recommended) fusible link.

It bypasses the factory charging system altogether, however, it does not eliminate the factory fusible link on the starter relay from where the power to the inside of the vehicle is derived so the factory protection is still there.

THIS is why Powermaster says that there's nothing wrong with a "shunt" wire. Theirs is a shunt system, therefore, there's no problem with a shunt. That's NOT the case in any situations except with their one-wire alternator systems.

This is also NOT the case with a ChryCo charging system, however UNLESS you make the a fore-mentioned modifications to the ammeter but it's only a patch to help maintain proper voltage levels at the battery.

If you try and bypass a factory MoPar alternator in the same fashion, the same original fusible link on the starter relay will protect the body harness but the alternator output will NOT be protected unless you add an additional fusible link in your shunt wire but that's still not going to cure your problem.

The reference voltage for your voltage regulator comes off the ignition circuit and if you have faulty bulkhead connections, that reference voltage will be incorrect and your charging system will STILL be screwed up.

The fix, as has been mentioned before, is to repair/replace the bulkhead connections, not a kludge shunt bypass, and THAT will solve your problems, .

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Let me get this straight, you are talking about an added parallel wire run (shunt wire) from the alternator output stud to the battery(or the battery terminal on the starter relay), with or without its own circuit protection(optional apparently), overlaying (shunting) the original intact (or somewhat intact) charge path wiring and components, you say this will not alter the stock circuit protection for all the unfused stock wiring in any way? If so, I would refer you back to post #32 of this thread for further info on that. This shunt wire bypass will indeed negatively alter the stock circuit protection to the point of being completely useless in the event of a short, Kirchhoff's current divider rule, no way around it. May have to break out the fixture once more for another video and demonstrate to total failure, stay tuned.

AC car, running headlights and blower motor on high = never a balanced system at idle on a muscle era mopar.
Same ol stuff with a boatload of qualifiers. The system itself, in a factory car, has never caused a problem, so some say, and that is just NOT TRUE. Jump starting a dead car and having the bulkhead go hot, lovely. Off to ignore, had enough of that.

The stock system is a dumpster fire with the packards which aren't even rated to carry the base alternator 37ish max load... that is a POORLY designed system from the GO. A well designed system should be able to carry the max load limits without failure creeping into the environment. Mopar missed the mark BADLY here. Put a SS hemi in front of a 3 clutch pack 904 and when it fails, don't be surprised. Same here, engineering or bean counters screwed the pooch.

Denial just isn't a river in Africa.

The Shunt wire with a fusible link will provide protection but it raises the failure point very high. The stock fusible link has allowed MANY cars to roast the instrument cluster/dash harnesses in these cars... they aren't the panacea of protection either.

Per Powermaster: Bypass your ammeter; repair/replace old packard connectors; install a voltmeter; run 8 or 6 ga. shunt wire directly to + battery from alt. output; can even install a 120-125 amp Mega fuse or breaker (depending on what alt. output is) in the shunt line to protect everything should the alt freak out. Give them a call if you are confused.

Should be playing golf said:

Per Powermaster: Bypass your ammeter-no need; repair/replace old packard connectors-repair? bypass the Packards, weakest link of the entire system; install a voltmeter-no thanks, useless information, may as well run an idiot light; run 8 or 6 ga. shunt wire directly to + battery from alt. output-no thanks, very dangerous; can even install a 120-125 amp Mega fuse or breaker (depending on what alt. output is) in the shunt line to protect everything should the alt freak out-the current potential of the battery is a bigger concern . Give them a call if you are confused-I'll pass on that.

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Stupidest thing I've read in a while for sure, I see the tie in to DDG now. Again, better hope you never experience a short circuit in any of the stock unfused wiring or components because wiring will burn with that described “shunt wire” in place. Total and complete circuit protection matters. Too many years wrenching at dealers and later designing and building high power 12-volt charging and load distribution systems for vehicles of all types to be confused about parallel circuits and simple basic overcurrent circuit protection dos and don’ts, like never parallel(shunt) circuit protection devices. I’ll stick with my Tuff Stuff 130amp alts, appropriately modified wire sizing, correct load placement, a functioning stock ammeter and properly designed full circuit protection for my builds. Now I remember why I don’t buy Powermaster.
Again, have no need to be calling Powermaster. I’m not confused at all on this matter. Stepping off this merry-go-round of a thread now. Have a fire extinguisher handy always if running this shunt wire bypass, shorts happen. cheers.

There is good ppl defending this, but just will post some quick phrases to reinforce:

-“one wire alt” is not the same than “high output alt” by default. One is how is wired to make it work about its fields sourcing not how must be wired after its output stud. The other one is its output capacity. These alts can be one, or the other or both at the same time. But one thing doesn’t mean automatically the other.

-an amm registres the load going to or coming out from the battery. So NO MATTER the output capacity of the alt, the ammeter is not directly influenced or affected by.

-sure a higher output alt affects to the amm just at one stage, when the battery is highly discharged and will claim for recharge load. JUST at this moment the higher alt capacity will “negatively affect” the ammeter. BUT STILL ON THIS STAGE, since amperes are not pushed in by any source but requested, the amperage running thought the ammeter will be JUST what the batt is able to claim at his own chemical process speed. You can’t speed up the battery recharge more than what is able to process. Otherwise a higher ouput alt actually will “positively affect” the ammeter being the more load will be able to be sourced from the alt instead from the battery. This reduces or stops the power coming from batt, so the battery discharge/recharge stages is reduced allmost to zero. Less discharge/recharge stages affects positively to the ammeter being the ammeter a BATTERY status gauge, not an alt gauge.

-everything on this JUST as far the extra accesories (if some added) are CORRECTLY sourced from alt side like the original system is designed, NEVER from the batt.

-you can get a thousand amps alt, but if the system just requires 45 amps, the alt will provide JUST that. Amperes are requested by the accessories, not pushed in by the power sources. Just like on your home outlet plugs your phone charger or the iron. Your home wall outlet is designed to handle around 15-20 amps, and your phone charger maybe needs barely .5 amps to recharge your phone. It won’t burnt just because your wall outlet along with its breaker circuit is able to handle 20 amps, coming out from a Main breaker system of 60 or 100 amps, on an EVER GREATER amperage capacity circuit coming out from the city network. Just like on your car feeds your starter motor the same than your glove box light with a 400 or 900 amps load capacity battery. And the glovebox light won’t burnt. Your glove box light will keep still requesting the SAME .10 amps maybe no matter the power source capacity

In EVEN LESS WORDS.

A higher output alt will keep the battery out of the game while engine is running, specially while idling which is the biggest problem of factory alts. A battery out of the game means also an ammeter out of the game. Being out of the game it means no amperage running throught the ammeter.

This is true of course as far the original design is respected, meaning NO ACCESORIES OR UPGRADES BEING SOURCED FROM THE BATT SIDE OF THE AMMETER (batt, starter relay stud… ). Any ACC on batt side makes amperes running throught the system like charging a batt. Wrong reading and unnecessary stress to the system.

This last is some of the real causes of burnt system of the original design… incorrectly sourced accessories. Aside the poor capacity of the bulkhead paths.

72RoadrunnerGTX said:

How much current do you believe will open one of these ammeters? If the battery is completely flat (discharged), how do you get it started?

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Jumper cables.

Crank it over and the engine goes into high idle once it starts and that 120+ amps that the alternator is capable of pumping out goes THROUGH the ammeter to that battery that is sucking it through the 60-rated ammeter and, thus, turning it into a fuse.

If you have problems with your ammeter circuit, that ain't all that's wrong.
All of the power to run your car comes through that bulkhead connector and, before the ammeter, it splits off and services all of the vehicle's circuits. The only current flowing through the ammeter after you replace the voltage lost during starting the vehicle is just a trickle charge on the battery.

Bypassing the alternator circuit with an under-the-hood shunt does absolutely NOTHING to remedy the loss of current-carrying capacity of the marginal bulkhead connectors.

You haven't fixed the REAL problem, you've just kluged up a symptom-elimination patch.
Every electrical system in the vehicle depends on good, tight bulkhead connections.
Loose and dirty bulkhead connections get hot with use.
Every time you use the heater, wipers, headlights, etc., you are deriving your current through these faulty bulkhead connections.

The ONLY thing you have eliminated with the shunt is the ammeter itself which wasn't the problem in the first place because ALL of your system loads are tapped into the alternator circuit BEFORE passing through the ammeter.
The ONLY time current passes through the ammeter is:
(1) when the engine ISN'T running in which case the battery is supplying the current.
(2) the alternator isn't charging, again, in which case the battery is supplying the current.
(3) when the alternator is replenishing the voltage drained off during start-up and,
(4) once that has stabilized, the voltage regulator keeps the alternator output just barely over the the current being used by ALL of your electrical systems and is trickle charging your battery.

You DON'T need an ammeter to run a charging system. You can use a volt meter, instead, to monitor the condition of the charging system. That's why Powermaster exists. Their method of connecting the alternator directly to the battery DOES work and is a valid method for their application but, and that's a big "but" if you try and use their technology on an older ammeter style circuit as a repair for dim headlights, slow wipers, etc., you had better make damn sure that the power getting inside the cabin is not being compromised by worn, overheated and/or corroded bulkhead connectors.

Adding your own shunt or switching to a high amperage Powermaster alternator is not a valid substitute for inadequate bulkhead connections. You also have to address to real reason for the "upgrade" and replace the brass terminals in the bulkhead connector. (or replace the under dash and engine bay harnesses)

Basic charging system with an ammeter.



The shunt does NOTHING to repair the poor connections in the bulkhead connector and the current STILL has to pass through that connector regardless of whether there's a home made shunt or a Powermaster alternator.