sometimes you need to use a flat bladed screw driver and gently turn the pump impellor at bottom, they sometimes stick, do this without tap on, then try
working the tap on and off, I sometimes need to do that with the bathroom tap if laid up a while, and it eventually springs into life, as though some contacts needed cleaning
try a light incase 12v battery flat
if you have a heater fan try that to see if work, have just discovered the 7.5 fuse 2nd down on the bip works the heater fan and kitchen tap on my troll, it may be differently wired on yours..
hope you manage to restore
regards P