Topic: battery
in Forum: C3 Electrical
Well I finally drove my vet home to finish a few things. I live about 35 miles from town which turns out was about 15 miles to far. Battery was at full charge while driving and I don't know why, when put signals on I could see the guage jump back and forth so obviously something not quite right yet. Looking for ideas
Lifetime MemberAlternator is not doing what it should. If you had all Wiring disconnected, check to see if a possible wrong connection. Had it happen on mine.
If you are saying the car stopped while running and the battery was dead then I suspect your alternator is bad because a car will run without a battery if the alternator is good.
1973 L-82 4 spd
Lifetime MemberModerator
It is normal for the alt/batt gauge to fluctuate some with the turn sigs or flashers on. If the gauge was pegging all the way to the discharge side, then that's a problem. I know you did get the car home, but did it die on the way? If not, put a multimeter on the battery and check the charging voltage at idle and about 2000rpm. If the charging system is good, and the battery tests good, then you may not really have a problem...just normal operation, imho.
Joel Adams
C3VR Lifetime Member #56 
My Link 
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
It is normal for the alt/batt gauge to fluctuate some with the turn sigs or flashers on. If the gauge was pegging all the way to the discharge side, then that's a problem. I know you did get the car home, but did it die on the way? If not, put a multimeter on the battery and check the charging voltage at idle and about 2000rpm. If the charging system is good, and the battery tests good, then you may not really have a problem...just normal operation, imho.
adam what readings should I be looking for at idle and at 2000
Lifetime MemberModerator
Should be showing anything above at least 13v. You would normally expect to see 14-14.5 AT the battery while running, if the charging system is working properly. Gauges on these cars are notoriously inaccurate, but as long as it is showing a charge, you should be good to go. Charge voltage really won't change much from idle to 2000rpm, most of the time. Just make sure you see at least 13v with the headlights on, and the blower on "High". Also, compare your gauge reading with an actual voltage reading on the battery itself(with a multimeter), so you can compare what the gauge says VS the actual voltage at the battery. You'd be surprised at how much difference there can be sometimes between the two.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
You can also take it to most auto parts stores and they will test the alternator and battery for free.
1973 L-82 4 spd
This was a complete rebuild, battery is new and alt is good, just wanted to see what other peoples guages were at, so much good info on this site, im sure i will get used to guages, just kinda nervous that first trip out that something doesnt blow up. Lol