ammeter

Anyone have an ammeter installed in your Deuce? Personally, I think it is a better indicator of whats going on with the electrical system than just the charge meter. Lets you know the condition of the batteries better and how quickly they are coming back to full charge etc. Any thoughts?
Thanks,
BC

I wasnt aware that any vehicles equipped w/ an alternator had ammeters , I thought they were all voltmeters (charge indicator), the early trucks w/ generators all had ammeters orignally. It requires a 'shunt' be designed into the wiring to accomodate an ammeter an they were found in the old mechanical type regulators but not the later solid state ones. Perhaps someone else knows more, perhaps some s.s. regs did have shunts and the extra wiring needed? And yes ampmeters did show actuall charging output, whereas the voltmeter only displayed avial voltage and a discharge situation would go on awhile before it showed up on a charge indicator.

Hey gwalker, exactly why I asked. Have an old Chris Craft with generator, two batteries with selector switch, and ammeter. Watch ammeter and charge each separately until charged. I know you can't charge individually in a Deuce, but would be nice to know how much they juice they are taking. Perhaps it would take an electronic "magic box" of some sort to put one in a alternator system, don't know. Will have to research that. Maybe OPCOM will chime in here with some info.
Thanks,
BC

You could add an ammeter into your truck but you would need to add some wiring. The voltgauge only needs a power wire and a ground to work. An ammeter has to be 'inline' with the power flow, say in the wire coming from the alternator to the battery, however the gauge couldnt hold up agianst that much actuall current so a shunt is added to the wireing so that a portion of the current is directed through the ammeter. Vehicles w alternators sometimes do have ammeters but for some reason the military didnt want them when the alternators an s.s. regulators were introduced. You could add in a shunt an the extra wiring to utilize an ammeter yourself, A magic box isnt required it fairly basic, some aftermarket gauges are actually internally shunted so you dont have to do it yourself.

In the M880 series of trucks, the ammeters were of the non shunt type and took the full output of the small 12 V alternator thru the dashboard as I remember it, or if shunted, still carried enough current to break the soft solder and then there was a problem with arcing and melting and many fires in the dash resulted...Not the separate 24 volt system with alternator and two additional 6TNs for radios etc...with Voltmeter..

I can't say I like one system over the other. They both really tell you the same. Charging system output is based on system voltage, system voltage is based on charging system output... High loads twitch either needle. Different gauges have to be interperited differently. The big benefit to an ammeter is they are (typically) in a better resolution than a voltage meter. The drawback to am ammeter is that it's (typically) a high current device with all the issues typical to such.

If you're WORRIED about the charging system, a good resoution volt meter (that is, a voltage gauge with a resolution that is impractical for an analog dashboard display) is the first tool that anyone is going to grab.

$.02 only. This is a hobby after all. In my book that means that if one wants to see amps instead of volts displayed on the dash, one should certainly be seeing amps instead of volts displayed on the dash...

Re: RE: ammeter

acetomatoco said:

In the M880 series of trucks, the ammeters were of the non shunt type and took the full output of the small 12 V alternator thru the dashboard as I remember it, or if shunted, still carried enough current to break the soft solder and then there was a problem with arcing and melting and many fires in the dash resulted...Not the separate 24 volt system with alternator and two additional 6TNs for radios etc...with Voltmeter..

Click to expand...

I have had a couple of Dodge instrument clusters that melted down.

I prefer ammeters.

On my Mopars from the Sixties, they have an ammeter (which sometimes results in the same kind of problems Ace mentioned in the M880 series). If you are seeing a discharge in the system, you can isolate the problem between the alternator and regulator (seperate regulators on old Mopars).

It's a nice diagnostic tool when you're a long way from home.

C