1995 E320 electrical weirdness

[FLYGEEZER]

124,000 miles without a glitch, up until now. Started off with dead battery last week. No surprise as it was four years old. R2'd with a new one. When attaching the negative post I noticed a slight spark . Suspicion sent me for the multimeter. Discovered I had a .68 ohm draw with ignition off, all doors closed and no ultities on. The car is totally stock. No aftermarket add ons.Began the diagnosis by removing fuses one at a time to isolate the drain. All fuses removed and still no change. Leads me to believe the drain may be in an unfused circuit. Engine wiring harness was replaced in 1998 by the recall. Ops, I mean campaign. Then I found other, unseen or un-noticed before, anomalies. The radio & automatic antenna has power and operates with the ignition off. I suspect this might be a failed diode for the door open power seat operation. But that doesn't explain why I have no check engine light on with the key in the #2 position. The check engine light does illuminate, however, very dim with all fuses removed. but goes out and stays out with fuses installed. I'm sure I have a queertron running around some place, but where? The questions before the house are: Could the draw be the unfused alarm system and where can it be disconnected? How does one get the damn diode out of the fuse box and does it have anything to do with the inop check engine light? Sorry about the long rant and thanks in advance for any help.