Trying to figure out the parasitic drain a friends 2000 mazda 626 has. Nothing is on that i can think of. However his alternator is going bad (only puts out 9.5 v at idle) When the car is completely off the battery drains slowly but very steadily. It's brand new so it's not that. However when i unplugged the positive wire leading to the battery the battery stopped draining and jumped up a few volts due to nothing drawing from it now.

Pretty sure it's the alternator voltage regulator possibly being crudded up and causing this. Any insight?

 

reconnect the battery and pull the positive wire that goes to the alternator off to know for sure man. Altho trying to troubleshoot one problem when you know you have another isnt very productive. If the alternator needs to be replaced then why not replace it and see if the issue is gone in lue with low charging. Or take it to advance and have them load test the battery and alternator.

And last, just because a battery is brand new doesnt mean that it cant be bad. Factory defects are becoming more and more common with the cheap out sourced labor these days.