mdkrp

Any help is appreciated:
So the Alternator warning light was on after the car was turned off and I did not make much of it at the time as I was in a hurry.
Attached the battery tender on as usual (battery was replaced with new one approx 2 months ago). I tried to start the car a couple weeks later and nothing- no start or even a crank.
I thought battery was dead (maybe a bad unit?) so took it out and tested it and did not register on voltmeter. So I attached battery tender to battery (unit is out of car) and left to charge up. Next day it registers about 34 mA so put batter back into the car and it now starts! But...the Alternator light stays on even after I turn car off.
I am assuming there is a battery drain somewhere? If so what is best way to track this down? Electrical is not my strong point. 😣
Thanks

oldskewel

what kind of car?

The charging light you show there is supposed to be lit when the key is turned to ON, but the engine is not running. When the engine is running, that charging light (alternator / battery light) should go out.

A battery tender could charge so slowly that it would take a long time to fully charge a battery. A voltage measurement would be helpful. I would not conclude a parasitic drain yet.

When the engine is running, the voltage across the battery posts should be around 14+V. If it is around 12V, that indicates the alternator is not charging.

Sorry if I'm keeping it too simple here.

theiceman

sounds like your ignition may be staying on ?? sounds like it could be something simple like ignition switch ? other things can be . Is the CD box squealing too ?
funny that the engine woulld turn off but alternator light stay on , never heard of this one .. usually it just stays on after starting, not stopping.

Lorenfb

Usually indicates a shorted diode in the alternator, i.e. the B+ terminal of alternator is shorted to the alternator light terminal.

theiceman

yeah glad you chimed in , i thought so too but wasn't sure so didn't want to post anything being not sure, as pulling that thing is a bit of a bear.. usually detected by a current drain at the battery with everything disconnected except alternator cable.

mdkrp

Thanks for the replys; I have some answers to prior questions and an update:
Car is 1987 911- stock with AC
The light no longer stays on after car is turned off but does stay on very faintly on/off while car is on.
Car now holds charge and no issues with starting it up.

As an aside, I have been hearing this noise a few seconds after I start the car and then goes away. It has been present on/off for past year or so and I did not know what it was from but am wondering if its related.
I am attaching a sound file; hopefully, it works.
Any thoughts?
Thanks

Lorenfb

So the problem was an intermittent problem, and over time it basically fixed itself, right?

mdkrp

Basically yes at this point. I was just hoping to make sure the issues I raised were nothing too serious.
I will continue to monitor the noise after start up and see if anything else happens. I did check the fan belt tension just by hand and it did not seem loose but probably will get a measurement tool to verify.