I question if my volt meter is working properly.
My thought is that it should usually read between 12 - 14 volts and when the needle sits on 13 I figure it is good. Mine is at 13 sometime but more often it is less and often at about 10. Now I am not sure if it is the gauge or the system.
First question. Am I correct that it should read at least 13 most of the time?
Second I was thinking that I could hook up my hand held meter and drive and compare the two. The question is where should I hook up the power source for the meter?
I then can compare the two readings and hopefully determine what the system is doing.
Thanks for any ideas.
elamott

I would tend to think the volt meter is reading correctly.

When the engine is not running and the key is in the run position the voltage may read something like 12 volts. After you start the car and have the engine RPM at something like 900-1,000 RPM then the voltage should go up to something like 13 volts or up higher.
If the engine RPM is not high enough at idle then the voltage may not come up if any as the alternator is not spinning fast enough.
If you are driving down the highway with the engine up around 2,000 RPM, have the original headlights on, the original AC on, and the original stereo cranked up the voltage should be and stay at anywhere from 13 volts up to a little under 15 volts. If the alternator is weak or has a problem it might slowly drop.
If driving down the highway you kick on a set of aftermarket driving lights, crank up an aftermarket 2 gigawatt stereo system and notice the voltage going down, down, and down, then the alternator is not large enough to supply the demands of these aftermarket add on's.
Factory gauges will all read a little different as they are not closely calibrated compared to a good set of aftermarkets or a good aftermarket volt meter.
You can certainly compare what the gauge you have now reads compared to a second or third gauge but if all are working properly and are connected to the same spot then they should both swing or work in a similiar fashion. One gauge may read 10 volts while another reads 12 volts at one spot in time but then if then the one gauge reads 12 volts then the second should read around 14 volts (both showing a 2 volt increase).

Vehicle wiring and connections deteriorate after time and using the wiring under the dash may show a lower voltage than right at the battery or alternator.

Jim

First check your alternator belt to make sure that it's tight...a loose belt will cause exactly what your describing. No need to drive the car while testing the voltage. Test at the battery posts (where the cables attach if it's a dual connection battery...both side and top post connections) The reading you get at the battery, when it's running is what the alternator is feeding back to the battery to keep it charged. If it's 13+ volts your good...if it's less, then your battery is slowly being drained...you should be able to hear the voltage regulator kicking in and out while watching the multimeter. If the reading is less than 13 volts...once again check that belt for tightness...if it's still reading less than 13...you have a bad voltage regulator which is internal (in the alternator)...time for a new one. If your gauge in the dash works at all...then it[s most likely giving you a correct reading. You should also check your battery connections before running out and buying a new alternator...especially the negative cable where it attaches to the motor...yeah it's a pretty crappy way that Chevy attached it...I moved mine to the block. Did I say check that belt for tightness...yeah ok, I think I did!:dontknow:

check the fuseable links for intermitten shorts,or any loose wires to the starter and altonar.:cali:

Thanks for the help. That confirms my thoughts, now to check it out.
elamott