My Battery seems to be discharging overnight. Tried two different good batteries and still the same problem. Their are no obvious things like lights on, radio, etc. Are there any know drain paths associated with the C3's? When recharged and taken for a run, the gauge reads charging.

Yea When I first got my vette, I could not keep the battery charged for more than a full day. After some investigation I found my non working car alarm wiring in the center counsol was hot with the car shut off. Since too much of the old system was butchered and missing from its colorful history I decided to just remove all traces of the old antiquated alarm. problem solved no more drain. now it may not be the same for you but you may try using a ampmeter and probe your fuse box to figure out what system is sucking the power. That will get you a better idea where the short/problem is.

if you dont have an ammeter.. just pull some fuses out and use a process of elimation to find the current leak..

Ayelander,

I have the same problem, only it takes about a week to drain the battery.

Until I get a chance to look into it, I put a battery disconnect (green knob) on the negative post & I unscrew it while the car sits. No ground, no drain. The only downside is that I lose the radio stations.

If you go this route, do not attach the fusible link, it will provide enough of a ground to allow the battery to drain.

I believe that my problem is in the courtesy lights, I just haven't figured out exactly where.

I also attach the "Battery Tender" during long periods between uses.

If you do figure it out, please point me in the right direction.

Good luck,

Anthony

I had a similar problem. Found that the door contact switches (door ajar and lights) were bad. The key buzzer was drawing too, the buzzer didn't make any noise so that was a little hard to find. The key buzzer started working on it's own after a few weeks, but sometimes, it just goes off without the key in the switch. New switch by the way.

Why do I seem to always agree with CTHULHU....and why do I always seem to respond 30 minutes or so after he also replied... lol

Anyway do as he suggested...

Just grab a ampmeter and pull a fuse...check the darin oin the barrety and repeat until you find the bad circuit...then narrow it down to the faulty item...

Bob

Remember... these are old cars, battery drain can be from just old wiring. When I first startd rewiring my car I tryed using the original wiring harness, and I couldn't get the drain out. When I bought the painless wiring fuse block and have now rewired the entire car from scratch using all the same relay's and electronic componets, I have no battery drain at all.
Just my 2¢

If you have disconnected all the fuses and the drain is still there, disconnect the alternator leads. The diodes sometimes fail and cause a constant drain. The alternator is repairable without a replacement.

I also had one that drove me nuts. Come to find out the horn ring was broke and someone just unpluged the horn so it would't honk....but it still had power going to it.
Drove me nuts.

If the ammeter is not available you can pull the negative battery cable and put your 12 volt test light in series with the disconnected cable and the disconected post.If there is a draw the light will light.The test light bulb will light dimly for a small draw and brighter for larger draws but you can proceed with the pulling of the fuses one at a time and note when the light goes out for an immediate visual feedback.This will at least isolate the culprit circuit and reduce the number of components to then disconnect one at a time (with the fuses back in).If you have a courtesy light timer these can sometimes be the problem along with any number of other things.Hope I helped.
Jules