Mike, Thanks for the heads up! Got this from
Wolfgang's ML Page: M-Class GPS cellphone antenna and it appears that the splitter/amp does require power. I need to look at the components more to see if that is needed. I may just break down and pull the old Antenna and put the new on in it's spot.
The MCS supplies +5 Volt across its antenna input (center to ground). The center pin of the GPS antenna in the rear should thus have 5 Volts on it. This also confirms that the coax leads all the way through, and is not interrupted like in 2001+ European models without Tele Aid under the passenger front seat.