Feed not working post upgrade

Just upgraded from a dual nozzle J end to the E3d hotend. Updated the firmware as instructed. As far as i can tell, Machine's running okay except that i can't get the feed to work. Doesn't feed to print and it won't feed if i try to run the Purge sub.

Heating/main cooling fan/BL Touch all seem to be operating as normal (as far as i can tell), just the feed servo. (i haven't seen the continuous cooling fan run yet either, but i haven't run a full test with this feed issue).

As far as i can tell, i've hooked everything up alright (it was pre-built when i got it for the most part). Maybe a firmware setting i've missed?

many thanks for any help.
Edit: Apparently, I'm just a silly person. The motor cables from the previous dual extruder got mixed up.

New problem is that the extruder motor seems to be running backwards. is this possibly a firmware issue? Using a calibration print from before the changeover that worked fine as is.

Also, does the continuous cooling fan (the little guy clipped onto the extruder) only run above a certain temp?

(still fishing through the firmware for settings on these things, but haven't built the confidence to change anything yet)
OK. Found it in the firmware and reversed the motor.

It's in the configuration.h file. I just set the #define INVERT_E0_DIR line to true (was at false by default) in case anybody else needs to find it.