New owner, wierd charging issue.

[86vettePA]

Recently purchased this car, fixed a few issues to get it running. Now I'm having a strange issue with battery discharge. I've tried this with two separate batteries and I'm starting to suspect the starter. Put freshly charged battery. Start car. Settles to idle 13.9-14.1 on the gauge, 14.3 at the battery with a voltmeter let run at least 15-20 minutes everything seems fine. Shut it off. Try to restart and the battery is at like 11.8v on the dash acts like it's dead. Any ideas? The starter is sounding kind of beat even when fully charged. I feel like it's killing the battery instantly, when I try to restart it. Or is this a wierd alternator diode problem. I did a continuity check on the alternator and it seemed fine. Also check checked continuity from the alternator to the distribution block and distribution block to battery. Any ideas? 1986 l98.

 

[LLC5]

Recently purchased this car, fixed a few issues to get it running. Now I'm having a strange issue with battery discharge. I've tried this with two separate batteries and I'm starting to suspect the starter. Put freshly charged battery. Start car. Settles to idle 13.9-14.1 on the gauge, 14.3 at the battery with a voltmeter let run at least 15-20 minutes everything seems fine. Shut it off. Try to restart and the battery is at like 11.8v on the dash acts like it's dead. Any ideas? The starter is sounding kind of beat even when fully charged. I feel like it's killing the battery instantly, when I try to restart it. Or is this a wierd alternator diode problem. I did a continuity check on the alternator and it seemed fine. Also check checked continuity from the alternator to the distribution block and distribution block to battery. Any ideas? 1986 l98.

It sounds like a bad battery. Always the first place to start is to have a fully charged battery load tested with a real carbon pile load tester, even with brand new batteries. You need to prove that the battery is good before any diagnosis.