I purchased a K-Line K29212 set at a swap meet yesterday - this is a Rio Grande Alco PA A-B-A set. All 3 units have smoke and both A units are powered with dual motors. A series of 8-pin connectors links the B unit and trailing A unit to the lead where the R2LC, DCDR, and RS boards reside. So the B unit and trailing A unit are "slaved" to the lead A unit.
This set runs pretty smoothly once it gets going, but the powered units jerk around some (possibly starting and stopping separately at different times) and the set struggles to start moving - I basically have to hit speed 3 on my CAB-2 to get them started and then dial it back so they're not rocketing around the rails. Sounds, smoke, and couplers all work fine and respond to commands from CAB-2, so I suspect this behavior is lack of cruise control and an aging/weak DCDR. However I'm curious if this is a symptom of the wiring setup as well - long connection from lead A unit, through B unit, to trailing A unit for motor control?
Has anyone installed a Cruise Commander M in a set like this? Any issues with a single CC-M driving 4 motors? Any issues with the long wiring connection from lead A unit to trailing A unit? I'd love to hear about some success stories or gotchas others have encountered doing an upgrade like this.