Why bypassing the ammeter is a GOOD idea!

[Nacho-RT74]

In think the original material calls masonite or something like that?

Sometime ago there was new ones being offered on ebay on $2 for the pair.

 

[Nacho-RT74]

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.

Where you will be sourcing the relays? From the batt? Big mistake! The load will run through the ammeter like the batt is being charged all the time headlights are on. This is the kind of mistakes being made all these years. Then blame the ammeter. Of course the ammeter should hold this load, but are the ammeter studs and isolators in good conditions after 40 years of abuse under underrated alts to keep holding this?

Source the relays from the alt side is the correct setup, like factory did, being sourcing everything from alt side of the game, but once again, will need the correct alternator to source everything. And on this stage the relays will be saving really the tired headlight switch points and terminals from the load, not really the ammeter itself. I am running relays from the alt side of the ammeter studs using 55w/90w halogen beams. I installed relays into the cab. Added 4 more relays to the AC/Heater blower speeds, because 73 and laters blower lever switch is REALLY weak. So I'm running safelly 6 relays into my ammeter stud. Never gets heat there because everything is clean and tight, bulkhead parallel path, upgraded alt and still stock +/-40 amps. I can see my ammeter centered. No move there it means no load. No load no heat. What made this? A good alt and tight contacts.

 

[moparnation74]

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.

Personally, I do not disagree with your rationale and I also am fully aware of ruling out other potential gremlins....I had a 68 dart and a 72 duster bypassed for over 20 years and no secondary problems...I guess it was not long enough for them to show "other" culprits, lol...

Now when I am restoring a car would I do that? Nope, I go the VM route. Well with a voltmeter conversion you have everything done internally...and you clamp the + and - together just as a bypass. Which is why in today's world that is my personal #1 option....number 2 would be a restored amp gauge....

Bypassing is a band aid but it works very well when needed....ohhh and safe....Hence, the term bypass you bridge that gap for when you feel like replacing it or decide to do a full restoration...

Maybe the OP can chime in on how the rest of his car is functioning....

 

[Nacho-RT74]

Like circuit board material?

That's probably a good one, just be sure nothing of the copper layer is there. I guess that material can hold heat ( if some comes ) without get burnt or crack easily, nor melt.

Personally, I do not disagree with your rationale and I also am fully aware of ruling out other potential gremlins....I had a 68 dart and a 72 duster bypassed for over 20 years and no secondary problems...I guess it was not long enough for them to show "other" culprits, lol...

Now when I am restoring a car would I do that? Nope, I go the VM route. Well with a voltmeter conversion you have everything done internally...and you clamp the + and - together just as a bypass. Which is why in today's world that is my personal #1 option....number 2 would be a restored amp gauge....

Bypassing is a band aid but it works very well when needed....ohhh and safe....Hence, the term bypass you bridge that gap for when you feel like replacing it or decide to do a full restoration...

Maybe the OP can chime in on how the rest of his car is functioning....

Nice! As I told is to each one, but under the correct concepts

 

[Speedbird]

Reading through this thread makes me think of this....
Tea time and English cars.
This thread is a prime example of why I don't think I'll be posting tech help any more. (lol)
Gawd. I didn't use spell checker.
Hoep eye didn't mispell anythig.
(I'm monolingual)

 

[moparnation74]

 

[Derwud]

Reading through this thread makes me think of this....
Tea time and English cars.
This thread is a prime example of why I don't think I'll be posting tech help any more. (lol)
Gawd. I didn't use spell checker.
Hoep eye didn't mispell anythig.
(I'm monolingual)

Ha-Ha, thanks for proving my point..

 

[Speedbird]

Ha-Ha, thanks for proving my point..

Sorry, I'm confused more now.
So, they removed the voltmeter to install an ammeter before the fire?
Or was your point about putting batteries in backwards?

 

[Derwud]

Sorry, I'm confused more now.
So, they removed the voltmeter to install an ammeter before the fire?
Or was your point about putting batteries in backwards?

The English make crappy cars..

 

[The Rebel]

Really good info here as working on my electrical system is one my next projects.

Someone posted this on here somewhere: https://www.allpar.com/history/mopar/electrical.html

 

[moparnation74]

Really good info here as working on my electrical system is one my next projects.

Someone posted this on here somewhere: https://www.allpar.com/history/mopar/electrical.html

Allpar has great articles!

One key to note and was also in the article was the use of dielectric grease...Fill it up...I could barely snap on the harnesses to the bulkhead due to the bulkhead from the main dash harness was full of grease for each pin on the X....Eliminate any chance of air/moisture....

 

[Ranger16]

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. 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.

Be careful. That was my problem and I made a new insulating strip, but when I powered it up, I fried the fusible link. I suspect that there is another insulting strip inside the gauge that had aged and began disintegrating as well. That was the final straw that made me bypass it.

 

[72RoadrunnerGTX]

Be careful. That was my problem and I made a new insulating strip, but when I powered it up, I fried the fusible link. I suspect that there is another insulting strip inside the gauge that had aged and began disintegrating as well. That was the final straw that made me bypass it.

There are no internal insulators in these ammeters. The two original insulators, one on each side of the frame, are notched and keyed to the pot metal frames to keep the studs centered, to the prevent the studs from contacting the frame where they pass through the frame. If the replacement fabricated insulators are not accurately reproduced with these notches there is potential that the studs will ground to the frame.
In the op’s picture, on the undamaged end of the pictured insulator, one of the these notches can be seen.

 

[SwedCharger67]

440+6 said: ↑
I still have my amp gauge, and I like it.

I also have the original ....

Me too, with a modern 100 Amp alternator, and I'm not worried.

Like Nacho said, there is nothing wrong with the ammeter itself, just lack of maintenance and a loose nut has overheated the connection.

 

[Nacho-RT74]

Be careful. That was my problem and I made a new insulating strip, but when I powered it up, I fried the fusible link. I suspect that there is another insulting strip inside the gauge that had aged and began disintegrating as well. That was the final straw that made me bypass it.

There are no internal insulators in these ammeters. The two original insulators, one on each side of the frame, are notched and keyed to the pot metal frames to keep the studs centered, to the prevent the studs from contacting the frame where they pass through the frame. If the replacement fabricated insulators are not accurately reproduced with these notches there is potential that the studs will ground to the frame.
In the op’s picture, on the undamaged end of the pictured insulator, one of the these notches can be seen.

I guess he meant about the internal insulation, not inside the gauge, but between gauge and cluster housing. If so, once again the fail was about unknownledgement and not the system or the design... again. Don't blame the gauge once again, you simply didn't know there was another insulation inside the frame, and just replaced the one outside ( visible )

Which in any case, those who bypass the amm attaching both together to one of the stud, will need to take care of the insulation too, BOTH INSULATORS, because you are keeping the ammeter still hot! If insulation is damaged ( outer or INNER one ) will short too the same than is not bypassed.

Soooo, are you taking care of this guys ? Then will blame to the ammeter again even being bypassed on this way LOL.

 

[Ranger16]

I guess he meant about the internal insulation, not inside the gauge, but between gauge and cluster housing.

No sir, I actually did mean inside the gauge, but that was just a guess on my part and apparently I was wrong about that. I thought the insulator I made was good, but apparently I was wrong about that too and blew it (as well as the fusible link ). At any rate, right or wrong, I felt it easier and safer to simply bypass the thing and rely on the volt meter.

 

[Nacho-RT74]

welll.... mmmm the gauge itself doesn't handle any ground signal inside, just positive. Weird.

I can think just on the gauge face or rivets isolation failure ? that would be the first time I heard that, since they never get stressed on anyway.

 

[al383]

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. When you get an oil valve seal failure, you simply replace them, and don't blame the valves! Or do you?

With the propper checkouts on an old car and correct mantenience, you can get your ammeter running safe forever.

Just need to take serious your car electrical like the rest of the car everybody does.

STOP MINIMIZE THE ELECTRICAL PARTS OF YOUR CARS!

;)

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.

What is the correct charging balance I have a 69 Super Bee that is overcharging all the time

 

[Nacho-RT74]

The load balance is given by the ammeter, but to get that need to have running a quite powerfull alt on car. On any car the correct ammeter reading should be the closer to the center as posible. That will mean the alt is sourcing the car demands without being assisted by the batt when is not capable.

What do you need ? Consider all the regular devices will operate on car regulary, know the load they require to work and get an alt able to provide that while engine is iddling, but not the max output! Need to source everything at the lower RPMs as posible.

This includes ALL the lighting system including brakes hazzard and turnings, ignition system, Radio... wipers and Heater/AC blower if posible at max speed both. Or med speed at least.

Powered windows, cigar lighter can be obvioused because they operate for short time really.

Doesn't hurt have occasional charge readings, meaning at certain point the batt sourced anything on car being discharged, but doesn't have to be the rule.

If you have a constant charge reading without batt being sucked out previouslly it means:

You could have a damaged batt.
You have added accesories between batt and amm
You have poor contacts on the charging system so the batt never gets fully recharged and all the load produced to recharge the batt is being lost on heat around

 

[Speedbird]

The load balance is given by the ammeter, but to get that need to have running a quite powerfull alt on car. On any car the correct ammeter reading should be the closer to the center as posible. That will mean the alt is sourcing the car demands without being assisted by the batt when is not capable.

What do you need ? Consider all the regular devices will operate on car regulary, know the load they require to work and get an alt able to provide that while engine is iddling, but not the max output! Need to source everything at the lower RPMs as posible.

This includes ALL the lighting system including brakes hazzard and turnings, ignition system, Radio... wipers and Heater/AC blower if posible at max speed both. Or med speed at least.

Powered windows, cigar lighter can be obvioused because they operate for short time really.

Doesn't hurt have occasional charge readings, meaning at certain point the batt sourced anything on car being discharged, but doesn't have to be the rule.

Of you have a constant charge reading without batt being sucked out previouslly it means:

You could have a damaged batt.
You have added accesories between batt and amm
You have poor contacts on the charging system so the batt never gets fully recharged and all the load produced to recharge the batt is being lost on heat around

Thank you for taking time to explain things.

There is an English metaphor.
I do not know how it would translate into another currency.
"Penny wise and Pound foolish".
An amp meter meltdown (while possible) ignores a real safety issue if that issue is not addressed.
Driving (maybe) at night should be a concern.
After all, headlights are used.
At least in theory.
I think we all know the short comings. (Pun intended).

Just Damn.
Has anyone seen pictures of Arnold with his shirt off recently?
The grave is next.