Dad's wanting to add a couple gauges to the '04 in my signature. Since it's an Automatic, the trans temp gauge has taken the place of a volt meter. He wants to add a voltmeter, and an ammeter as well. He thinks an ammeter with a -60 -0- 60 range will be enough, but I'm a bit skeptical. I think it needs to be a -100 -0- 100 gauge. What's your input?

 

I will have to agree with your dad. Although the 100 will do the job i think the 60 will be more adapt to displaying a better resolution during the charging rate which is where the meter will be used most of the time. The biggest readings will be during start mode. Starters of today typically have lower current draws with higher torque rates that wont require you needing to display much above the 60. Automotive Ammeter gauges are generaly considered relative instruments and are generaly used for basic indication other than displaying a specific value unless you decide to get into a digital which use a analog to digital converter along with dampening circuits depending on cost.

 

Thanks for the input, Dave.

 

remember, it depends on how exactly you wire it in, but the ammeter should only measure charge/discharge of the battery.

a majority of the time it will read very close to 0.

if you are ever reading +/- 60 A, you've got troubles.

If you wire it in to measure alternator output, you don't need one with a '-' side, as it will always be a positive output.

 

You must be insane to want to run an ammeter! Maybe you don't know how dangerous those things are. You have to re-route the entire charge cable from the alternator to inside the truck to the gauge and then back to the battery. While in the process creating one very long extremely hot charge wire that can burn through and cause fire. You will also have to upgrade the charge cable to at least 2ga to handle the full 130 amp load. Not to be harsh but be safe and just skip the ammeter. Its not needed just do a nice safe volt gauge.

 

http://www.autometer.com/productPDF/0642E.pdf

Autometer doesn't say a thing about re-reouting the ENTIRE charge cable.

Also, If you can send me a link to something somewhere that says how unsafe ammeters are, I might give it a read. I've NEVER heard ANY horror stories about ammeters.

By the way, I take offense to my sanity being judged by a total stranger.
I'm here to try and learn. Not to be called an idiot.

 

^^^ From your link. If the alternator puts out 130amps plus the extra 10amps cushion they recommend equals a wire large enough to handle 140 amps. A wire that can handle 140 amps is a big friggin wire. I'm siding with ford390gashog.

There are other gauges that are more important to have than an ammeter IMO which are less of a hassle.

 

ALRIGHT THEN!!!! I WON'T PUT A FRIGGIN AMMETER IN THE DAMN THING!!! YOU WIN!
There...happy now?

 

You can get shunt style ammeters that don't require you to run the entire power/charge wire into the cab of the truck. I looked and couldn't find an example, but I know they exist.

I personally don't see the value of an ammeter but it can be done.

 

People are trying to help and you bring the attitude? Grow up.

BTW the 04' in your sig has a 5.4l 2V not 3V.(Unless you transplanted a 3V in it and somehow got it to work with the 4R100 and its pcm)

 

Here is an example of a shunt ammeter. And it's not terribly expensive.

Digital Amp Meter, 100A, 12V/24V/48V DC - Ammeters, Voltmeters, Battery Monitors @ AltE

 

Millenium,
Yeah i think you need to chill abit.

Although shunts are available view the PDF (you will need adobe acrobat or similar to view) for help with the hook-up.

You could eliminate the ammeter and use a volt meter. They won't quite display the discharge rate as quickly as the ammeter but the volt meter is alot easier/safer to connect.
http://www.egauges.com/pdf/AutoMeter/247e.pdf (scroll down to page 4 for the ammeter)

Here is a another basic hook-up of the ammeter.

 

I'm just goin by what the Owners Manual said it was. Guess I'm a goof.

 

Thanks for the links dchamberlain. I appreciate your help, but I've pretty much decided not to add an ammeter.

 

That actually is a very good way to add an ammeter if you want/need one.
In the AC world, high amperage measurement is done with a current transformer rather than the DC shunt resistor.
The point is, a self-contained ammeter needs to be able to conduct the maximum ampacity of the meter. A 100A 12VDC self-contained ammeter would be pretty big and the cables would be huge.
Properly wired, a 100A 12VDC self-contained ammeter would be perfectly safe but pretty impractical.
The reason the auto industry changed to voltmeters years ago was primarily for this reason as well as an ammeter tells you nothing about the condition of your battery, just your charging sytem. Inferences may be made, for example a high charge rate when very little systems are running may mean the battery is not charging.

Also, I would agree with you that personal knowledge is usually required to judge sanity; that is why my friends keep me sedated.