Three months ago I couldn't start my engine, the original battery (3 years old) had about 9 Volts, so I replaced it and that fixed engine starting problem. Yesterday it happened again, battery voltage was about 9V, I jumped started the engine and the alternator was putting out about 13.7V at battery terminals without turing on air condition, with AC on I measured just 12.3V. I don't have a current tester that goes 100+ Amp, to verify current from alternator to battery. Has anyone gone through this ? Is it a charging (alternator) or discharging (some short in circuits) problem? I really hate to replace a good battery or a good alternator.
thanks