Amp Gauge ?

[55 Fargo]

Hey all, my amp gauge in the Fargo is a 50- to +50, is this indicaitve of a 6 volt system, or a 12 volt system. I was doing some searching on this topic in Google, and came across a website, that stated 12 volt systems had 30 amp gauges and 6 volt systems used 50 amp gauges.

Now I understand the rationale for the higher amp draw with a 6 volt system, but would not the regulator and genny determine the flow of current, ie a 6 volt 30 amp genny, now I do not know how many amps the 12 volt gens normally were, as I have an alternator on mine.

So if anyone knows the answer can you enlighten Me......

[Don Coatney]

Anytime you have 6.241 X 10 to the 18th power electrons flowing through an electric circuit in one second you have one ampere irrelevent of voltage. Does this answer your question?

[Dave72dt]

Regulator, genny and rotational speed determine the output. Whether or not the gauge size is an indicator of 6 or 12 v system, I can't say. I've seen 6v systems with a 20 amp gauge. I don't recall seeing any 6 or 12 systems running more than a 60 amp gauge. At that point, common practice seems to be a volt meter or charge indicator light.

[Plymouthy Adams]

these numbers are often base current for Generators and will reflect actual or very close to the actual current flow.....alternators are generally a bit high output and thus the sampling of the current is just that..a shunted sample with usually only showing an indication of charge or discharge on the gauge...no true indication of current only that you  have current in a general direction of some metered amount...these will read an alternators output up to the limit stated...

Edited November 29, 2013 by Plymouthy Adams

[55 Fargo]

Anytime you have 6.241 X 10 to the 18th power electrons flowing through an electric circuit in one second you have one ampere irrelevent of voltage. Does this answer your question?

No it does not answer my?at all, but thanx for trying. The only point of this thread and ? is this. Apparently from info I read on another website, Mopar used a 50 amp gauge for the pre 1956 6 volt systems in Dodge trucks, and 30 amp gauges for 12 volt systems for 1956 or later. I am asking this question to those who can confirm this or refute this, nothing more nothing less.

 

Regulator, genny and rotational speed determine the output. Whether or not the gauge size is an indicator of 6 or 12 v system, I can't say. I've seen 6v systems with a 20 amp gauge. I don't recall seeing any 6 or 12 systems running more than a 60 amp gauge. At that point, common practice seems to be a volt meter or charge indicator light.

Thanx Dave, and those are my thoughts too. Not sure why this info suggest a lower amp rated gauge for the newer 12 volt systems from 1956 and later...

[Plymouthy Adams]

double the voltage halve the amperage

[Don Coatney]

double the voltage halve the amperage

That was my point that did not answer the question. One amp is still one amp no matter what the voltage.

[Plymouthy Adams]

^{lol yeah Don, I knew exactly what you posted...}

[55 Fargo]

double the voltage halve the amperage

Yes, this is not the ?, my 47 Chrysler had a 30 amp gauge, was it a factory 12 volt system, of course not, so why did it not have a 50 or 60 amp, hey everything is double the amperage, as you so astutely explained.

Edited December 1, 2013 by Fargos-Go-Far

[MBF]

I think what they're trying to tell you is that with a 12 volt system, the amp draw / requirements are half that of that 6 volt system that was previously used.  What Chrysler may have done is to change the scale of the amp guage because the higher amp flow would no longer be needed to be shown since the power requirements were less.   Mike

[55 Fargo]

I think what they're trying to tell you is that with a 12 volt system, the amp draw / requirements are half that of that 6 volt system that was previously used.  What Chrysler may have done is to change the scale of the amp guage because the higher amp flow would no longer be needed to be shown since the power requirements were less.   Mike

Mike I already know how ohms law and amperage varies 6 volts versus 12 volts. I really do. i am on a fact finding mission to discover what gauge was used for the 12 volt application. I really don't care what amount of current it measures, just if it were changed to accommodate the switch to 12 volts.

thanx for your post and concern, this post was not meant to educate Me on ohms law and the differences in 6 or 12 volts, just what was possibly changed by Chrysler....

Edited November 30, 2013 by Fargos-Go-Far

[MBF]

I just reread your original post a couple of times.  I know that there were different amp ratings on generators that was usually shown on a tag on the generator.  I would assume that when the vehicle was built that they would match the original rating of the generator to a similarly scaled amp guage.  I'm pretty sure that my 1 ton rack body has a different amp guage than my 2.5 ton of the same year.  I'll have to check tomorrow.  The 2.5 ton was originally a firetruck and had a lot of lights and two radios-I'm sure that had a bigger generator than the smaller truck.  I could confirm this, but the 1 ton was converted by me to 12 volts (alternator) several years ago and I no longer have the generator that was on the truck when I got it.

[55 Fargo]

I just reread your original post a couple of times.  I know that there were different amp ratings on generators that was usually shown on a tag on the generator.  I would assume that when the vehicle was built that they would match the original rating of the generator to a similarly scaled amp guage.  I'm pretty sure that my 1 ton rack body has a different amp guage than my 2.5 ton of the same year.  I'll have to check tomorrow.  The 2.5 ton was originally a firetruck and had a lot of lights and two radios-I'm sure that had a bigger generator than the smaller truck.  I could confirm this, but the 1 ton was converted by me to 12 volts (alternator) several years ago and I no longer have the generator that was on the truck when I got it.

Yes that certainly could be the case, including an ambulance, requiring a lot more juice to support it's electrical needs. Again just trying to ascertain if infact Chrysler  did this amp gauge change for the 1956 year, purely for my own interest. Thanx again, I appreciate your input and help

[Plymouthy Adams]

Fred....has your amp meter been changed.

 

Hey all, my amp gauge in the Fargo is a 50- to +50, is this indicaitve of a 6 volt system, or a 12 volt system. I was doing some searching on this topic in Google, and came across a website, that stated 12 volt systems had 30 amp gauges and 6 volt systems used 50 amp gauges. Now I understand the rationale for the higher amp draw with a 6 volt system, but would not the regulator and genny determine the flow of current, ie a 6 volt 30 amp genny, now I do not know how many amps the 12 volt gens normally were, as I have an alternator on mine. So if anyone knows the answer can you enlighten Me......

the area in red is why no one takes this serious or I guess failing to see your real question here....the load of the accessories determine the amount of current flowing and the total current..the generator and regulator just determine the rate of the charge...rating of the generator for the car as designed is what usually stipulated the size of the amp meter...given if at 6 volt the circuits were rated high enough to warrant a 60 amp meter..then 12 volts would halve that given the exact number of cuircuits so technically the 30 would be sufficient

Edited November 30, 2013 by Plymouthy Adams

[55 Fargo]

Post Deleted

Edited December 1, 2013 by Fargos-Go-Far

[P15-D24]

On the 6 volt systems a 50 amp ammeter was used with the the optional heavy duty generator and regulator. The info is in the parts book.  I would assume a similar option was available for 12 volt cars in the later years. Voltage (6 or 12) doesn't matter, it is the size of the generator and regulator that determined the scale needed on the ammeter.  

[55 Fargo]

On the 6 volt systems a 50 amp ammeter was used with the the optional heavy duty generator and regulator. The info is in the parts book.  I would assume a similar option was available for 12 volt cars in the later years. Voltage (6 or 12) doesn't matter, it is the size of the generator and regulator that determined the scale needed on the ammeter.  

Thanx GTK, I read on another forum about the year of the change to 12 volt systems, so for my own knowledge only I started this thread. I consider this thread answered, and the matter closed

[Plymouthy Adams]

I am not blowing smoke..I an only commenting on the very facts you supply....if 60 in 55 and 6 then 30 at 12 in 56 then you basically answer your own question...and again...check with the parts books....are you wanting to know if your meter has been changed? logic has it that same circuits at 6 is basically twice that as 12...thus the higher current of indicated 6v meter..also as I posted on your thread about what was used on the 6 to 12 conversion ie resitors and CVR..I also posted the fact that later alternators in their higher output even at idle has shunted meters that just indicate current flow/direction and do not meter the current....I need not have Don chime in on this have my back...I am not blowing smoke anymore than someone is not taking a minute to go to his very book on the truck.  To that end consulting the parts book is going to be you sole conclusive source for the answer...I comment only on the logic for that change...

 

I comment on the area in red as I could not believe you think that current flow is regulated by the gen/regulator..only the charge rate/voltage is controlled...and with the generator engine speed is also important on return current to the battery..further...yur truck being a 55 should indeed have a 60 amp meter then you are so far ahead of the game..you could easily put on a low output alternator at 12 volts with no worry at all for over currenting..you could increase your trucks circuits to include fog lights, stereo power windows or other accessories  and get actual current flow/rate indication...given you very words that 55 = 60 and 56 = 30 I see no real need to duscuss further..check your build date...

[Dodgeb4ya]

I just looked at the Dodge truck master C series parts book-1954-56.   All C series trucks except 12 volt C-3 trucks use  part # 1500380 guage. C-3 1956 12 Volt trucks use a new higher part # 1660852 guage. Half ton through 4 ton.

I also looked at Ebay and Google. It appears 1954-55 6 volt trucks with cloth wiring used the 50 amp guage and the 1956 plastic wiring 12 volt clusters used the 30 amp guage.

So I would assume 1956 uses a 30 amp meter guage.

Bob

[55 Fargo]

I just looked at the Dodge truck master C series parts book-1954-56.   All C series trucks except 12 volt C-3 trucks use  part # 1500380 guage. C-3 1956 12 Volt trucks use a new higher part # 1660852 guage. Half ton through 4 ton.

I also looked at Ebay and Google. It appears 1954-55 6 volt trucks with cloth wiring used the 50 amp guage and the 1956 plastic wiring 12 volt clusters used the 30 amp guage.

So I would assume 1956 uses a 30 amp meter guage.

Bob

Thanx Bob, this confirms what i had read on another website.

[55 Fargo]

Okay had some time to do some research today. The gauges for 1956, with the exception of the oil pressure gauge are designed for 12 volts for the gas and water temp gauges. The ammeter was lowered to measure 30 amps.

The 1955 6 volt gas gauge and the engine temp gauges I have tested, and they both were working well. I am not sure I have done any damage to either, or if the gauges could tolerate the momentary input of 12 volts. The 12 volt gauges look identical, but have different part numbers. So I either can source the 12 volt gauges or use runtz voltage droppers on them...

[Plymouthy Adams]

the gauges are electrically the same 6 or 12 it is the application of the CVR on the 12 system that makes it all work correctly...ohms law not needed here..just a working knowledge of the vehicles electrical system..

Edited December 3, 2013 by Plymouthy Adams

[Don Coatney]

Where can one aquire a working knowledge of the vehicles electrical system?

[Plymouthy Adams]

well Don, Personally if I would look in the shop manual or online by typing just a word or two...starting with using this if not a CVR designed by the factory..the standard resistor does not prevent the surge of power

http://www.unbroke.com/runtz_guides.html

Edited December 3, 2013 by Plymouthy Adams

[55 Fargo]

http://dodgepilothouseclub.org/know/pw_parts/pw_8.pdf

 

Here is the link with the parts list for these gauges, 6 volt for 1955, and different parts listing numbers for 1956 and later. Now they look identical, and I could not find any reference or part # for a CVR for this set-up, not saying it isn't part of the equation.

Yes Tim a standard resistor would not control voltage surges, thus allowing potential damage. The CVR unit say like the type used for a 1960s Mustang, would provide a consistent flow of 6 volts to the instruments, without damaging surges.