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Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2443309
01/30/18 11:29 AM
01/30/18 11:29 AM
Joined: Feb 2003
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Manitoba, Canada
DaytonaTurbo Offline
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How about an aftermarket ammeter? Good aftermarket ones are of the shunt type that do not require the full current to actually travel through the ammeter. I have a 100A stewart warner ammeter on my shelf with two tiny little connection poles because the full current does not travel through the ammeter.

Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2511634
06/22/18 09:15 AM
06/22/18 09:15 AM
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Maryland
wally426ci Offline OP
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I hit the snooze on this one. Sorry! I am back at it.

Nacho, I've wired the system as shown in the MADD diagrams where it goes from Alt to starter relay and then into the cab. THe only exception is that I do have connectors at the firewall.

It sounds like I cannot get the reading I want unless I go back to the old routing?

How about a shunt style gauge? How about a gauge under the hood for periodic checks? Would I simply enter between the Alternator and the Starter relay stud?

I do appreciate the notes.

Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2512052
06/23/18 07:46 AM
06/23/18 07:46 AM
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Valencia, España
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the only way to get a full load ammeter working is getting the wiring up to the stock configuration. Any parallel path to the stock wiring jumping out the ammeter will eliminate the correct ( or any, if some ) amm reading. The ammeter needs to monitoring ALL the load coming in or out to the batt.

the only exception is a shunted ammeter, where the ammeter gets a built in coil amplifier able to move the needle with a minimun load going through based on a known resistence shunt. Shunted amms are a remote reading of the load going thought the shunt and they are wired like this:


Main charging wires-system with shunt outside1.jpg
Last edited by NachoRT74; 06/23/18 07:47 AM.

With a Charger born in Chrysler assembly plant in Valencia, Venezuela
Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2512053
06/23/18 07:50 AM
06/23/18 07:50 AM
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Valencia, España
NachoRT74 Offline
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otherwise, the stock wiring on full load ammeter is and MUST be like this.

( Bulkhead disposition is 71/74 B body based, maybe also E )


Main charging wires-system.jpg
Last edited by NachoRT74; 06/23/18 07:52 AM.

With a Charger born in Chrysler assembly plant in Valencia, Venezuela
Re: Setting up an aftermarket AMP gauge? [Re: NachoRT74] #2512154
06/23/18 01:30 PM
06/23/18 01:30 PM
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north of coder
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if a guy has an aftermarket amp meter, is it possible to add a shunt, and if so, what value would it be ? this would be on a custom built harness, nacho.
beer

Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2512460
06/24/18 07:03 AM
06/24/18 07:03 AM
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Valencia, España
NachoRT74 Offline
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Ammeter with shunts are specific to be used with a matched shunt. They usually are sold as a set.

Mopar used this system since 75/76 and even could be used from a later model ( studs gap is the same ) but would need to get the shunt wire from the same car too.

I have a 78 F mody ammeter I'd like to use on my car just changing the face, but have no idea about how much must be the resistence of the shunt on this to convert my car on a shunted system, and by now have no found literature about this, maybe just getting a harness from this car with the shunt intact ( have no idea if I could get the shunt wire from another Mopar yet )

78 LeBaron ammeter


With a Charger born in Chrysler assembly plant in Valencia, Venezuela
Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2512462
06/24/18 07:22 AM
06/24/18 07:22 AM
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Valencia, España
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This is a 76 A body ammeter ( one year only ). Check the last pic and will notice the coil attached. This is an amplifier to move the needle with a minimum load, since these are not anymore full load ammeter, but is based on a resistor shunt with specific specs.

76 A body ammeter on ebay


With a Charger born in Chrysler assembly plant in Valencia, Venezuela
Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2519426
07/09/18 08:42 AM
07/09/18 08:42 AM
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Maryland
wally426ci Offline OP
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You the man Nacho. Thank You!!

Re: Setting up an aftermarket AMP gauge? [Re: wally426ci] #2519459
07/09/18 11:51 AM
07/09/18 11:51 AM
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USA
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If you have an shunt type ammeter you can use a battery charger and a length of bare NiChrome wire salvaged from an electric heater to determine how many ohms the shunt should be to make the meter read correctly. Use a couple of electrical “jumper” wires with alligator clips at their ends to vary the length of NiChrome wire, making it a temporary shunt whose ohms you can vary. Standard industrial shunts typically are 100 milli-ohms or 1.00 ohms.

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