Glass fuse on the backside of the receptacle. Charger won't come on at all if this is burnt. Could be a weakened relay in the charger? You just have to eliminate the possibility of a bad connection, then maybe jumper the charger relay and see if that keeps the charger on.... also does it have an AC circuit breaker on the charger? Those get weak and pop like corn kernels.
This will give you some areas to work ...
