Battery wire help.

Morning all, anyone know where the black wire should go, it’s come offf from somewhere and battery not working. Thanks James. 

Black wire from what? Pump, charger, back pack?

Black wire is normally negative and attaches to the - terminal of a battery but if you're asking where it goes then you're not seeing a missing wire from the battery..

Post photos, maybe someone will recognise your equipment and be able to help.

The black wire comes from van mount pump. Does it go on the positive battery terminal?

Thought I’d sent the pic in first post. 

It must need crimping on the negative looking at it. 

A black wire goes to the negative terminal, I would recommend getting some decent ring connectors as all the wires look like they are about totally frayed, only a matter of time before they all go, looking at them 

Thanks for the replies, my customer is sorting it all with new ring connectors as we speak ?