[SILVY968]

I want to add an Ammeter gauge into my 968 engineering cubby panel. Yes, the FLUBBER will have to go. I have found the gauge at egauges

http://www.egauges.com/vdo_mult.asp?Type=A...es=Vision&Cart=

but I do not know which amp range I should select. They have a 60 amp and a 100 amp. Also which gauge wire to use and how to best wire the gauge into the system.

Has anyone done this on a 968?

If not, any advice would be appreciated. I don't want to blow up the DME or anything else for that matter!

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[Greimann]

Consider the implications before spending too much money on this just yet. An ammeter needs to have all of the vehicles electrical load passing through it EXCEPT the starter load. Look at the positive terminal at your battery. All of those wires except the starter cable will have to be collected to another point , run through the ammeter and then back to the terminal. You are talking about running at least a 4 gauge or fatter wire into your center console where the total battery capacity of the car is now collected at this narrow point. where a stray short could create some nice fireworks.



Also, the theoretical charging capacity of the alternator is over 100 amps, so even the best gauge is not rated to handle it. I think a more accurate volt meter that is wired directly to the battery would be safer and more informative.



Ammeters were common on older, simpler cars, but you never seen one on modern, electrically intensive vehicles.

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[flash]

dave is bang on here



while i want one too, i have not looked into what to do to make the gauge a "remote" so i wouldn't have to run the 2 guage cable necessary to handle the current



as he said, it was easy on older cars that only put out 60 amps, but now with 105 on this alternator...............



sounds like a project for somebody - eric?????????

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[Brian]

couldn't you run some kind of remote?

measure it at the battery and then send it via some kind of small gauge wire?



i'm guessing you'd need some kind of sensor at the connection to actually do the measuring.

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[flash]

i'm pretty sure you can - i just never gave thought to what would be needed to get there - i get all tangled up when i start thinking about resistance, relays, and such - dave and eric are better at that than i am

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[Greimann]

There are inductive ammeters, but those are usually diagnostic devices. I have not seen one offered as an installed instrument.

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[Dirk]

The typical Ampere meter for a car would be a (milli) Volt meter that is wired on top of a resistor in the main power lead from the battery.

That resistor will be pretty big to sustain the regular loads expected (Flash mentioned 105 Amps.)



For the sake of the example it's easiest to take a 1 Ohm resistor, for every Amp passing through it there will be a 1 Volt drop measured over it.

So obviously useless in a 12V. automotive set-up.



Let's assume a 1/100 Ohm resistor, at the mentioned 105 Amps charging current we will measure 1.05 V. across the resistor.

Here a 1.5 Volt range Voltmeter would be a nice selection.



Maybe you don't want to loose up to 1 Volt, in that case a 1/1000 resistor combined with a 0.15 V range meter would be the choice, that way you'd only loose about 0.1 Volt charging Voltage.



I'm sure such kits are for sale.



Oh yeah, induction-type meters don't work on DC current, only on AC.

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