Why bypassing the ammeter is a GOOD idea!

[moparnation74]

I don't trust inline ammeters. They may be fine for a long time then "what's that smell?".
A better design to monitor current is to use a current transformer like we do in the industrial world.

Yeap....makes me think of this song, lol....or someone

 

[patrick66]

The ammeter didn't fail, but the isolation gasket did. It got craked due heat and missed the piece with car vibrations, so is not really an ammeter gauge failure. You need to take care of the electric parts like everybody takes care of brakes or carbs, which also gets gaskets stressed and you tipically replace

Then also get the correct charging balance which IS NOT the factory setup... they really did a big mistake on alt outputs rates from factory.

So, who the hell routinely checks their ammeter, or routinely replaces one? You? You make it sound like it was a case of improper maintenance or neglect. Guess what? Parts fail! They do, really! And yes, it was indeed an ammeter failure. Note how the connection from the post to the gauge is warped from heat? Sounds like an ammeter failure to me! No, it's not something you repair or fix; you replace the gauge, or bypass it altogether. PS - Spell check really is your friend.

 

[72RoadrunnerGTX]

That’s not a failed ammeter, it’s a heat damaged ammeter. Heat generated by the single loose connection on the charge side of the ammeter. If the fiberboard insulators are not damaged from the ammeter mounting nuts having been over tightened during a past service, and if the ring terminal connection nuts remain properly tight, there will be no resistance to generate the heat to damage the ammeter as pictured.

As mentioned by another poster, these cars were never designed to last this long. The ammeter by design is robust and with tight connections, should last indefinitely. It is a more accurate gauge to the state of battery charge/discharge than a basic volt meter. The charging circuit running through small Packard connectors in the bulkhead connector is the weakest link of the original design, by-passing the bulkhead connector, tight/good ammeter connections, making sure all additional loads are on the alternator side of the ammeter (not at the battery), will make for a fully functional, safe, ammeter based charging system.

 

[Glenwood]

if the ring terminal connection nuts remain properly tight, there will be no resistance to generate the heat to damage the ammeter as pictured.

Loose connections cause arcing, which results in excess heat as it appears on the op's ammeter. Dirty/corroded connections can add resistance, but still tends to cause arcing in the case for old, melted bulkhead connectors.
The ammeter may indeed last indefinitely, if everything in the circuit remains as it was new. No additional loads, clean wiring & connection points and not subjected to additional heat. Perhaps the ammeters were engineered to too tight of a tolerance for changes with age. I wonder why they are not widely used in today's vehicles?
A voltmeter tells me all I need to know about the integrity of the charging system.

 

[moparnation74]

Loose connections cause arcing, which results in excess heat as it appears on the op's ammeter. Dirty/corroded connections can add resistance, but still tends to cause arcing in the case for old, melted bulkhead connectors.
The ammeter may indeed last indefinitely, if everything in the circuit remains as it was new. No additional loads, clean wiring & connection points and not subjected to additional heat. Perhaps the ammeters were engineered to too tight of a tolerance for changes with age. I wonder why they are not widely used in today's vehicles?
A voltmeter tells me all I need to know about the integrity of the charging system.

That is a key point to note!

The voltmeter is accurate enough.....I agree...

 

[Nacho-RT74]

I have aditional loads, use the A/C and got a powerfull alt with a 900 reserve load amps battery, daily driver. Everything running safe on the stock "weak and unratted +/- 40 amps ammeter" with a allmost steady centered needle.

Guess what ? a fully discharged batt won't suck more than 40 amps ever. Chemicals inside are not able to be so fast to get the electrochemical balance back, so a 40 amps ammeter is quite enough. Of course is not safe to get running that load for long time on a car, but still ammeter is able to handle it. Still if you get a full charge or discharge reading for some time something is really wrong on the car, and a 40 amps gaue will tell you that. Then it's up to you if you decide still work on that stage, but don't blame the ammeter.

You need to know how to play with it, thats all.

Don't you replace carb gasket when they fail ? when it fails do you blame the carb ?

Don't you replace valve oil seals when they fail ? when they fail, do you blame the valves ?

Once again, that ammeter is still good, just clean tighten back the stud/shunt assembly ( needs to be somehow smashed/hammered ), new isolation and done. The bad spots on stud are caused by the short itself, but not from a previous fail. MY OPINION ( not saying that is THE reason, but it can be very well that ) is you got lot of discharge and charge readings coming from the factory underrated alt allong the years. This unnecesary loads coming through the ammeter can get some heat there and get loosen the studs from the ammeter shunt due the heat on metal, loosing the pressure there ( they are installed by pressure with a press ), getting more heat because that lossen stage, then damaging the isolation, untill cracked and get in touch with cluster housing.

and yes, on a resto job, I make mantenience on everything, gauges and wiring included.

I'm wondering if you ever advertised you could be getting constant discharge readings, and back and forth needle movement when giving gas to the engine and if you really understood what it was happening there. Do You ? I'm not blamming you just wondering! I actually blame to Chrysler on this, but owners knowledgement on this specific area helps on save this tipical failure... and there is LOT of unkwoledgement about this specific topic.

Also source everything correctly from alt side of the game, never from batt side. TIPICAL HUGE MISTAKE from owners and even those so called "techs" on ammeter equipped cars

As far you really understand how an ammeter works and what is really testing, you will appreciate the gauge.

Two big mistakes were factory made, underrated alts and call that gauge ALTERNATOR which really is not! is really a BATT gauge. An alternator NEVER get discharged, is not an acumulator... it sources the power( which is not the same than charge ) or not. The batt is what gets charged or discharged. But the alt sources whiche ver on the system is... it can be charging or not. Maybe in fact is not charging, because the batt is full, but that doesn't mean is not sourcing the rest of the car

Does a centered needle ( neither D or C reading ) on a running engine it means the alternator is not working ? NO, is just right the opposite! it means the alt is sourcing everything the car is needing, without get the batt sucked out. that's the perfect stage. So a centered needle on a gauge called ALTERNATOR could mean the alt is not working for lot of ppl! Ppl doesn't understand what the ammeter reading means.

and, thanks for the spell check advise. I'm not from USA and is not my mother language... I can make lot of mistakes! ( I don't see spell check on the reply box on this board, but anyway I never use it where is present... what about if you help me out on what I did wrong and I can learnt from my mistakes? )

 

[moparnation74]

I have aditional loads, use the A/C and got a powerfull alt with a 900 reserve load amps battery, daily driver. Everything running safe on the stock "weak and unratted +/- 40 amps ammeter" with a allmost steady centered needle.

Guess what ? a fully discharged batt won't suck more than 40 amps ever. Chemicals inside are not able to be so fast to get the electrochemical balance back, so a 40 amps ammeter is quite enough. Of course is not safe to get running that load for long time on a car, but still ammeter is able to handle it. Still if you get a full charge or discharge reading for some time something is really wrong on the car, and a 40 amps gaue will tell you that. Then it's up to you if you decide still work on that stage, but don't blame the ammeter.

You need to know how to play with it, thats all.

Don't you replace carb gasket when they fail ? when it fails do you blame the carb ?

Don't you replace valve oil seals when they fail ? when they fail, do you blame the valves ?

Once again, that ammeter is still good, just clean tighten back the stud/shunt assembly, new isolation and done.

and yes, on a resto job, I make mantenience on everything, gauges and wiring included.

I'm wondering if you ever advertised you could be getting constant discharge readings, and back and forth needle movement when giving gas to the engine and if you really understood what it was happening there. Do You ? I'm not blamming you just wondering!

Also source everything correctly from alt side of the game, never from batt side. TIPICAL HUGE MISTAKE on ammeter equipped cars

As far you really understand how an ammeter works and what is really testing, you will appreciate the gauge.

The first mistake was factory made, calling it as ALTERNATOR gauge which really is not! is really a BATT gauge, since an alternator NEVER get discharged, is not an acumulator... charges or not. The batt is what gets charged or discharged.

Does a centered needle ( neither D or C reading ) on a running engine it means the alternator is not working ? NO, is just right the opposite! it means the alt is sourcing everything the car is needing, without get the batt sucked out. that's the perfect stage. So a centered needle on a gauge called ALTERNATOR could mean the alt is not working for lot of ppl! Ppl doesn't understand what the ammeter reading means.

and, thanks for the spell check advise. I'm not from USA and is not my mother language... I can make lot of mistakes! ( I don't see spell check on the reply box on this board, but anyway I never use it where is present... what about if you help me out on what I did wrong and I can learnt from my mistakes? )

Nacho

Just chiming in on your post....I do not disagree with what your stating above. However, the OP made a safety point and it is "safe" to bypass it. Another alternative is to do a voltmeter conversion.

The OP being the owner of his car did what he thinks is safe for him and his ride, I get that....With his gauge messed up he probably doesn't want to remove the cluster to replace the gauge. The gauge may be OK but thats he unknown and the OP took the easiest safest route...I cannot fault that......

I personally have had amp gauges last forever....I also had some fail....ever since those failures I chose an alternative....While someone is periodically "maintaining" things....I am sitting at a show or in my house drinking tea....

In other words it is one less thing to piss with.....

 

[Nacho-RT74]

I edited a bit my previous post.

hey, I'm agree ppl can like or not the ammeter and everybody decide his own route, but everytime I post about this, is just cleaning the concepts. Lot of ppl take their decisions under a wrong concepts they read around without wonder theirself how the system works and what it was the real culprit. That's all. There is lot of ignorance on this topic.

The ammeter is unsafe under an unsafe enviroment, just like is unsafe a gas line at a side of the coil, if gas line gets a leak, or coil wire gets an arch due broken isolation. And both live side by side into engine bay. If you don't keep safe those items, engine bay will get fire, just like the ammeter will get a short on a cracked isolation for whatever reason.

You can burnt your gauges if the voltage limiter gets somehow ungrounded. Just a few ppl knows about this, but.... is voltage limiter fault ? no! just that it is on that way! Now we have electronic replacements what can save this, but back in the days, that it was the technology available! You have the upgrade option now and no need to fit an autometer setup on your cluster! or simply clean and tight everything, make the mantenience to keep the stock voltage limiter still safe. So It could be a Voltage limiter fault ? no! is another fail what could made the voltage limiter get ungrounded untill burn the gauges! AND THE VOLTAGE LIMITER CAN BE STILL IN WORKING ORDER

You can get a big short too if the ignition switch wire gets peeled off and gets grounded.

Those were couple of examples where another kind fails can get some pieces fail without fail by itself and still be in perfect conditions!!!

now, what it was the reason the ammeter isolation got cracked and missed a section ? a good question to be answered!

what kind of readings the ammeter was getting all these years ? it was overlooked or taken seriouslly ? if the owner ( being the OP or not ) doesn't know what it means the ammeter reading, will blame everything but the correct piece or part of the game to blame.

So stop the ampophobia ( damn I really liked that LOL ) and learnt about this. Fear is beated with knowledgement. This kind of threads without the correct information just increase the "ampophobia" without need for that.

So I would say IF YOU GET THIS FAIL, IS TIME TO CHECK WHY IT HAPPENED!, not really THE REASON WHY BYPASS THE AMMETER.... because even bypassing the ammeter, the alt can be still not sourcing enough your car and batt, so will get another fail somewhere sooner or later for the same reason the ammeter "got failed" ( actually the assembly, but not the gauge itself )! You are not fixing the main problem, just the failed item due the main problem!

That's all.

 

[Derwud]

Even the English are smart enough not to use an in-line ammeter... And they build crap cars...

 

[72RoadrunnerGTX]

Loose connections cause arcing, which results in excess heat as it appears on the op's ammeter. Dirty/corroded connections can add resistance, but still tends to cause arcing in the case for old, melted bulkhead connectors.
The ammeter may indeed last indefinitely, if everything in the circuit remains as it was new. No additional loads, clean wiring & connection points and not subjected to additional heat. Perhaps the ammeters were engineered to too tight of a tolerance for changes with age. I wonder why they are not widely used in today's vehicles?
A voltmeter tells me all I need to know about the integrity of the charging system.

Arcing? You don’t need arcing to account for the heat damage pictured above. Resistance and current is all that is necessary to have that kind of heat damage. I don’t see any signs of metal transfer resulting from arcing.

Why aren’t ammeters used more today? Cost is the driving factor to automotive manufacturing trends. Voltmeters are much less costly and don’t require careful connections or a little maintenance for long term reliable service. Ammeters can provide more information than just whether or not the alternator is functioning. I wonder why ammeters were used by most all auto manufactures in the first 60-70 years of automotive history. Not to mention every other modern day vehicle types (aircraft, ships, trains) where full and accurate real time electrical information is critical and cost is not necessarily the first factor.

Run a Voltmeter if you wish, your choice, this thread implies that running an ammeter is inherently dangerous, just can’t agree.

 

[Derwud]

If you wanna be an Electrical Engineer while driving, great go right ahead.. Add pulling the Cluster and Blukead connector to your yearly automotive chores.. I enjoy driving more than wrenching, sorry modern cars have spoiled me!!
ampophobia is real and has a great cure!!

 

[Ranger16]

My experience was similar to the OP's. I attempted a repair and ended up frying the fusible link. Thank God for fusible links. Needless to say, I learned my lesson and the ammeter is bypassed. The voltmeter tells me all I need to know.

 

[Bruzilla]

It also helps to install headlight relays so you're not drawing all that power through the Amp meter when you're driving at night.

 

[Glenwood]

Here's a well written article on this subject that may be of interest.

http://madelectrical.com/electricaltech/amp-gauges.shtml

 

[72RoadrunnerGTX]

Here's a well written article on this subject that may be of interest.

http://madelectrical.com/electricaltech/amp-gauges.shtml

It’s the Mad Electrical article again, been around for a while. Some valid information there no question, follow the argument if you wish but it is targeted at Dodge’s attempt in the late seventies to move to a plastic ammeter (and plastic cluster frame), “click together” connections, and high output alternators in their truck production. Bad combination for sure. Have a late seventies Dodge truck, get that plastic ammeter out of it, by-pass the bulkhead connectors. Most of the ammeter discussion in this article does not accurately represent all Mopar ammeter applications from the ’60-early 70’s.

 

[WileERobby]

Ok, allow me to chime in on this topic. Having monkeyed around these cars for 5 decades, I've seen alot. Both sides of this topic have valid, and correct points. If the system is in good condition, it's perfectly fine. If not, trouble. Probably the simplest way to put it is, like the guy used to say selling the chicken oven "set it and forget it"... bypass the ammeter & forget it.

 

[threewood]

The best single mod in my opinion is bypassing the bulkhead connector packard 56 connections. When I pulled my ammeter I was surprised at how robust it was. I agree, it doesn't go bad. The insulator gets crushed and squeezes out or crumples shorting to the cluster housing. Does anyone make a better quality insulating strip? I have one car with all original, nice condition wiring. The other has a voltmeter mod, bulkhead bypass, and relays for the lights.

 

[Lionized]

The best single mod in my opinion is bypassing the bulkhead connector packard 56 connections. When I pulled my ammeter I was surprised at how robust it was. I agree, it doesn't go bad. The insulator gets crushed and squeezes out or crumples shorting to the cluster housing. Does anyone make a better quality insulating strip? I have one car with all original, nice condition wiring. The other has a voltmeter mod, bulkhead bypass, and relays for the lights.

You could make one using phenolic material and the old cardboard material as a template.

 

[threewood]

You could make one using phenolic material and the old cardboard material as a template.

Like circuit board material? I could probably make one with a dremel and file. I was just asking because my 62 dash is all stock and I should probably inspect it. Thanks.

 

[Lionized]

Like circuit board material? I could probably make one with a dremel and file. I was just asking because my 62 dash is all stock and I should probably inspect it. Thanks.

Exactly. Sheets are pretty cheap that thin.

It'd be nice to have access to a 3axis and pump a few hundred out.