Wrong Alternator?

If you don't mind I would chime in with a similar question? I got my car finally back on the road and did around 50 miles of test drives.

Yesterday I went for a first test drive in the night. With the head lights on, the blinkers quickly started to get very very slow and the Amperemeter was on the discharge side, but made it home. When I measure on the alternator output terminal to a ground I get around 11.45V - same reading as on the now low Battery - this test was done with the engine RPM up to around 2000rpm.

Since I did not test the alternator before, I fear that I drove all the time just using the battery as a power source. When I installed the new battery, the needle of the Amperemeter was slightly on the charge side, now the battery is almost empty and the needle is on the discharge side.

As @Mattex mentioned above, I tried then to ground the alternator (picture post #8), still the same reading on the Alternator output. The battery went now on the charger and I would like to get a new single groove pulley Alternator. Do you guys have any recommendations for a new Alternator? Here is what I found so far, but not sure about their quality and if they would work:

https://www.napaonline.com/en/p/RSE2131001?partTypeName=Alternator&keywordInput=alternator (preferred)

More Information for REMY 20160

https://www.autozone.com/batteries-...tured-alternator-dl7014/333476_478360_0_24379


I attached a few pictures of the VR and Alternator I have in the car:

Thanks, Wolfgang

IMG_20200708_130804660.jpg

IMG_20200708_122352265.jpg