After Market Ammeter?
- Thread starter coalman
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67Dart273
Well-Known Member
As much as I used to like ammeters I finally caved and went voltmeter.
Start by reading this MAD article, which covers a lot of ground as to inherent problems in these old girls
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
This might give you some ideas if you decide to "do" a voltmeter.
http://www.forabodiesonly.com/mopar/showthread.php?t=119480
Start by reading this MAD article, which covers a lot of ground as to inherent problems in these old girls
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
This might give you some ideas if you decide to "do" a voltmeter.
http://www.forabodiesonly.com/mopar/showthread.php?t=119480
If you keep the amp meter, just rewire it with a heavier wire in the same fashion the factory did. Open up a Chilton and read the diagrams. They will show exactly what it is connected to.
Trust me, you want to follow that above link and bypass your ammeter and the bulkhead connector. They caused a nighmare for me and my car's wiring was in excellent shape with no corrosion and stock output on the alternator. The ammeter wire overheated, fused into the surrounding harness and pretty much ruined my day. I def wish I had bypassed it..
goldduster318
Overzealous Car Modifier
Dump the ammeter.
When you think about it, it's job is to tell you if the alternator is charging or discharging, which it does directly provided the wires are connected to the right terminals. The issue is that it has to take all the flow, and the long wire runs sometimes don't charge the battery well...or distribute power to anything you added under the hood well.
So, in a way it's measuring "flow"...positive is running to the battery, negative away.
Now, let's think of the safer method that doesn't require all the current to flow through it - Voltage.
With voltage we know we have a conventional "12V" system...
-A typical fully charged battery has roughly 12.5V without the engine or any loads on
-Anything below 12V should be considered discharging
-A correctly functioning alternator should read at very minimum 12.8V to be working, and less than 15V under most circumstances.
So, basically voltage is about the same as pressure...which is resistance to flow.
No reason to take a chance with an ammeter.
When you think about it, it's job is to tell you if the alternator is charging or discharging, which it does directly provided the wires are connected to the right terminals. The issue is that it has to take all the flow, and the long wire runs sometimes don't charge the battery well...or distribute power to anything you added under the hood well.
So, in a way it's measuring "flow"...positive is running to the battery, negative away.
Now, let's think of the safer method that doesn't require all the current to flow through it - Voltage.
With voltage we know we have a conventional "12V" system...
-A typical fully charged battery has roughly 12.5V without the engine or any loads on
-Anything below 12V should be considered discharging
-A correctly functioning alternator should read at very minimum 12.8V to be working, and less than 15V under most circumstances.
So, basically voltage is about the same as pressure...which is resistance to flow.
No reason to take a chance with an ammeter.
Dang it goldduster, you're killing all the reasons the ammeter lovers say it's an important gauge... IMHO, an ammeter is one of the most worthless gauges you can install in a car.
A voltmeter will tell you right away if the alternator/charging system is working properly. This without the hassles of any ammeter wiring.
I build wire around products and other electrical products. If you have any questions, just like here, ask away!
A voltmeter will tell you right away if the alternator/charging system is working properly. This without the hassles of any ammeter wiring.
I build wire around products and other electrical products. If you have any questions, just like here, ask away!
nm9stheham
Well-Known Member
Ammeters work fine and always have. They show charge into/out of the battery in this setup (except for the cranking current); not current out of the alternator. Voltmeters are better for most people because it is easier for most people to interpret the indications. But they have limitations in what troubles they can indicate too. And buying a decent voltmeter is a lot cheaper than a good quality ammeter.
FWIW: My '62 car's ammeter is in good shape, connections and all, and will stay in as the car is so original.
FWIW: My '62 car's ammeter is in good shape, connections and all, and will stay in as the car is so original.
goldduster318
Overzealous Car Modifier
Next thing people are going to tell me they need a flowmeter in their engine because the pressure gauge isn't good enough!
The ammeter on my car was partially melted when I got the car. And so was the dash harness. You tell me if they work "fine". All a result of high resistance bulkhead connections and the long charging circuit combined with the very small factory wires.
FWIW? Sorry, it's worth about zero. Mine was the same. Connections looked brand new. The harness still failed. Time is ticking when it's such a simple upgrade
tanis4457
Well-Known Member
When I purchased my car, it came with some spare parts. One of them being the old wiring harness, I inspected the bulkhead connector after learning about the amperage problems with the bulkhead connector and found it to be melted.
So I would strongly recommend upgrading the wiring and bypassing the bulkhead connector for anything high amperage, the alternator and headlights are the main things that come to mind for me. If you wanted to run an ammeter I would bypass the bulkhead terminals as well and run some new wire, depends on what you want.
So I would strongly recommend upgrading the wiring and bypassing the bulkhead connector for anything high amperage, the alternator and headlights are the main things that come to mind for me. If you wanted to run an ammeter I would bypass the bulkhead terminals as well and run some new wire, depends on what you want.
As I have the car's instrument panel out, the wiring diagram shows a 12 gauge red with tracer going to an accessory circuit breaker. This wire was not on the ammeter. Anyone know what the deal is on this??? Thanks
GRRRRRRR, You didn't say what car or diagram you're looking at.
Not every build will have every wire shown. If the car came with towing package or some other accessory there would be accessory circuit wiring for that, trailer brake or whatever.
Most of us don't even have a clip in the accessory port to fasten that fuse in.
Just for the sake of saying.. when a rally dash got a tachometer that accessory was wired through accessory fuse. When the rally dash got a clock that accessory was wired directly from amp gauge to it without a fuse.
nm9stheham
Well-Known Member
FWIW... the later plastic ammeters were a lot worse to fail than the earlier ones. And harness/connection failures take place separately from the ammeters, so that is confusing issues. Ammeter aren't worthless if you know how to read them; voltmeters don't tell you everything either.
Regardless, Coalman is getting good help and advice.
67Dart273
Well-Known Member
You MAY have what is known as factory? dealer? "police / fleet / taxi" wiring. This is documented in some of the service manuals. Look for big black and red wires going through the firewall in separate grommets, that is separate from the bulkhead connector.
Otherwise, someone has "beat you" to a bypass project
67Dart273
Well-Known Member
I agree. I actually used to prefer ammeters. Some clusters are constructed in a way that the ammeter studs must "sandwich" everything together including the plastic. When the plastic gets warm and soft because of the ammeter current, "things loosen up." Then you have meltage
In this part of the country, I used to see a fair number of the melted ammeters just exactly like on the Mad site caused by various things, including winches and snow plow lifts
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
A photo I stole from Ramcharger Central. Yup. Melted
There is nothing to hold it all together. Obviously the nuts. But when the plastic softens, it all is now loose, and "makes heat" from current flow
mderoy340
Well-Known Member
Do the bypass mod. If you want to get creative buy an aftermarket volt gauge. Take the guts out and swap it in place of the OEM meter. I did this on my 73 and with key off needle is straight up; run position, shows full charge. Shoot a little orange paint on all the gauge needles while everything is apart and it looks factory original.
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