Whilst undoing the xtra terminals in my L322,the neg nut(the one on the shocky tower) disappeared in to the labrynth of the engine bay.

This was to get battery out to charge it properly,it seems to have gone down in voltage after l/h headlight blew the other night.

As yet I cant seem to find it.

Is it essential that the nut is replaced or not until I can get another one.
Don't seem to have spare one in my box of nuts.

Thanks