changed battery - now hardly anything works

[Klimo]

Let me clarify. The battery was new about 1 1/2 years ago. The car was sitting for about the last 90 days. Is that enough to completely kill the battery? My concern is that some things work and others don't. The blinkers work and I can flash the lights and there is air flowing through the vents and the lights in the ash tray and cig. lighter are on. No dash lights, nothing happens when i insert the key...

Thanks for your help