My Yamaha electric cart battery charger problem

[justme0987]

My Yamaha electric cart battery charger problem. When I connect the charger to the power outlet and without connecting it the golf cart, the three lights blink for a second every 7 seconds. When I connect the battery charger to the golf cart it keeps doing the same. it is not charging the golf cart
the charger is YAMAHA, 48 volt charger, multi-stage battery charger/ maintainer. MIDEL JW9-82107-02
ANY thoughts are greatly appreciated

[justme0987]

charger 2.jpg