Hello there,

so i stored my car for about 5 months. When i returned my alternator was seized up and not spinning at all. A garage replaced it and everything was working fine untill a couple of days ago when my car died on the highway. I replaced the battery and cleaned the connection. The alternator was giving 11.3 V when i read it out while my car was running. (The same Voltage i was getting from the battery, so at least the connection should be good?) But that means the alternator is not working. Before I replace my brand new alternator I wanna make sure that its not a different part.
A few key information: My battery light is on but turns off when my car goes over 2400 rpm. Before the battery light came on and my car was working the lights would get brighter with higher rpms/ the more things I had running the weaker they were.
Can someone help me identifying my problem?