[Golf cart guy]

Its kinda common for the speed sensor to go bad, after the batteries have been replaced on a tomberlin. Changing the speed sensor only should have fixed the problem.
Something else happened, between the battery change and the speed sensor change.

Open breaker, from what I have seen, is a blown fuse, but the question must be raised as to why you are getting another code. You just don't see a cart with a code, and a code. Problem came on the speed sensor change, something got shorted, so all bets are off as to what failed. Smoked controller is also a possibility.