Hi,
I have an Alltrax48500, like new, no mileage. 0-5k throttle. with cooling fan and fuse.
https://alltraxinc.com/product/sr-series/I have a 2011 model S, the controller was replaced 2 years ago, and I thought I had the same problem again.
I bench tested the replacement setup, but it was the MBB causing problems.
It's in the original box from D&D motors.
Paid $609 new, will consider $500.
PM me if interested.