The motor's worm gear shaft appeared to have an over-sized running end that goes into the bearing. It was binding and as it heated up eventually stalled the motor. The motor unit was replaced along with a burned out rectifier. The good news is that they were able to trace out specifically which mirco-chip on the R2L2 board had failed and replaced it. Total job was $105.
So I put the B unit back into the consist and all ran well for about 5 minutes until the current started rising, speed started dropping until the stall came. But it wasn't the B unit. It was the A unit. I'm not a happy camper!
Could it be possible that it has the same bad motor problem as the B unit. The symptoms are exactly the same. I'll take this to the shop and see what they say.
