To me it sounds like you're getting bad electrons from that new alternator or your wiring harness is shot. There are just too many other things going wrong.

Jim F is right too. W140s will always show a code. With as many failures as you have that sucker should be lit up like a Christmas tree.

Where have you tried pulling the codes from? OBD-II? The diagnostic port under the hood (the blinkey light)? Star Diagnostics?

__________________
"It's not about how fast you can go, but how well you can go fast."

Bob in Richmond

'97 S320 (LWB), Ruby Red Metallic, 73k miles
'97 S420V, Smoke Silver Metallic, 155k miles