Becker 3302 vs. Alpine 1910?

[BioPOWER]

All,

My OEM radio, a Becker 3302 ('99 E300 DT with Bose audio), is out of commission. I've purchased an Alpine 1910 as a replacement -- and it works, except for making sound from the speakers. Almost as if the amplifier isn't being powered on.

Quick specs:
OEM Becker BE 3302 "Audio 30", Mercedes P/N A 208 820 01 86 [03], S/N X1069561

New Alpine CM1910, Mercedes P/N A 208 820 11 86, S/N AL191011171187


Radios look identical on the face and all plugs fit, but I believe the new radio to be from a two-seater (SL or SLK) as there is no "fader" (front/rear) menu option.

Thoughts? Maybe speaker wiring diagrams could shed light on this issue.


Thanks!