|Re: Why would someone want a voltmeter? (archive)|
Posted by Tom M. on October 02, 1998 at 14:16:21:
In Reply to: Why would someone want a voltmeter? posted by Bill Fossett on October 02, 1998 at 11:51:30:
: I know there must be a reason, but why would someone want a voltmeter in their car. What would a voltmeter read - 12 volts? I've had amp meters and old pressure guages that were useful but a voltmeter? Please enlighten me. Thanks.
The best situation is a voltmeter AND an ammeter.
As the other replies show, the voltmeter can show if the voltage regulator goes out of whack But you have to know how to read a voltmeter, the voltage can go up to over 14 V in subzero weather. (The battery is charged harder in cold weather.)
You can also see when the battery is fading, when you start the car the voltmeter will dip to below 10 V. This assumes you get a REAL voltmeter, not one driven from the car's DME. They don't read at all until the engine fires.
(No matter how cheap and good digital volt meters get I will NEVER EVER sell my Simpson 260 analog meter. You can't beat it for this kind of thing!)
Then the ammeter can be used to see if the alternator needs a rebuild or the belt is slipping. A sure sign of this is to sit at a light at night with the headlights on and see the ammeter go to the discharge side. (Although I must say the belts you get today rarely need tightening, they're much better than the ones I grew up with in the '60s.)
Anyway, if I could just thave one I'd want a voltmeter. Way better than trying to figure what the CHECK ENGINE light means!