I'm wanting to replace my after-market gauges. Which would be better to use on a 68 Chevelle and amp meter or volt meter. Thanks for your help.

Harold

Ammeters can be risky to install if not done properly since all of the power must flow through it
Stick with a good voltmeter and wire it from the horn relay junction to get the full volts

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VOLTMETER, VOLTMETER, VOLTMETER, VOLTMETER, AND IT'S SIMPLE TO INSTALL. VOLTMETER, VOLTMETER.

I think that for ease of installation , a voltmeter would be the way to go, although I would just wire it to the IGN terminal on the fuse block, so that it only reads when the key is in the "On" position. Voltmeters do require a small amount of current to operate, and could drain a battery if left connected 100% of the time, particullary if your car sits for any long periods.

Ammeter, without a doubt, is the more usefull of the two meters. Sure, an voltmeter is easier install but is that the point? (An ammeter isn't that tough, really.)

The voltmeter tells you the votage level of your electrical system. If it is too low, that is an indication of a bad generator/alternator and you're running on the battery which will eventually (soon) be dead. If it is too high, that is a sign of a bad regulator. When the engine is a anything but an idle, the voltage from your generator/alternator is higher than 12 volts. It is your regulator that maintains the 12 volts, or there abouts.

An ammeter on the otherhand, tells you how much and in which direction, current is flowing in your system. Positive current is an indication that your system is charging, negative is that it is draining from your battery.

In my opinion, it can tell you much more than a voltmeter. It can even tell you that your battery cables or starter is shot!!! (If, when you go to start the engine, the ammeter goes to -40 or more but the engine hardly turns, then it is the starter. If it just move negative, then the cables or connector is probably not good.)

I'd be happy to give you more information if you need it.

(Electrical Engineer and '69 Chevelle owner)

You could install the VOLTMETER or the VOLTMETER. If it was up to me I'd put in the VOLTMETER

Personally, I use both. Since each gauge performs a different function, IMHO they're both valuable and not that expensive for the most part.

I hate electrical problems and like to monitor both the alt/reg and battery condition.

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Dale McIntosh
ACES #1709
Team Chevelle #92 Gold

Wait a second, It takes about 200 amps to turn a starter over. How would a amp gauge not wired in series with the starter cable tell me anything about a starting problem. Voltage would give you alot more info about a starting condition problem. If the battery was 75% charged or better(12.4-12.6) you can use the voltmeter to validate what problem you have. If the voltage drops below 9.6 durring cranking chuck the battery, if It's 11 volts you have to much resistance in the starter cable, if it's around 9.6 and you car isn't cranking well it's a bad starter or your engine is about to sieze. On the other hand ampmeters are cool illregardless of the voltage drop created by all the extra wiring in the charging system. People respect the fact you know how to instale the meter without causing a fire.

No ammeter is installed directly in series with the starter. It would require wire as thick as the battery cables to be run into your meter and back out again. Wire any smaller would be a fuse!

There are two positive connections to your battery. One directly to the starter (BIG and THICK) and one for everything else (t h i n). It is the thin one that gets the ammeter.

When cranking, even the thinner circuit draws pretty decent current. The starter solenoid and ignition are still on that circuit.

The ammeter used today are called dc shunt gauges. I think this was the only type ever used in passenger cars. They are not wired in series with the battery. Like an earlier post said, you would need number 6 wire or bigger. They are no more difficult to install than the volt gauge. Use both if you have the room.

Wally
Gold #67

Howdy,

Does anybody know if an inductive type amp meter is made for automotive applications, that sure would solve alot of problems. Is John Fluke out there?