Thanks doc, but now I'm even more confused. The battery is fine as far as I know. All power is working including the headlight flashing while the alarm is going. I did try to jump it last night but nothing.

So in thr early w124 there is no immobilizer? That would be quite a coincident to have the battery drain and the alarm malfunction at the same time if there's no relation. Does this mean I can disable the alarm, jump or swap the battery, and get Oldirty home?