Earth cable

[Jimg81]

Hi newbie

2006 Toyota Corolla Verso

I have had an intermittent starting issue for a while, most of the time the car starts first time, but occasionally I press the start button & nothing not even a click just a faint humming sound, tested the starter relay seems fine, I was starting to check I was getting good earthing from the engine then I  found this cable has came away from its conector, I thought it was an earthing cable but why the connector? 
It runs from just below the Battery, not under the Battery just past the Battery tray on the side of the wheel arch to to part of the engine in front of the passenger side. There is no part No. 

any ideas? Can I just replace with a single length of cable without the connector? 
any help would be appreciated 

JimG81

[flash22]

looks like a ground you can replace it with a normal cable you can pick them up pre-made cheaply even halfrauds sell them

[Jimg81]

Thanks flash 22

i just wanted to make sure the connector was not important, I’ll get a new cable fitted.