Ok, speakers..
From the ISO (adapter) you should have a white wire, connect this to the + left speaker
from the ISO there is a white wire with a black line/stripe, connect this to the - left speaker
from the ISO you should have a grey wire, connect this to + right speaker
from the ISO you should have a grey wire with a black line/stripe, connect to - left speaker.
That should be it...any other wires from the ISO, fold the end over and wrap them individually in insulating tape then maybe just hold them together with a cable tie to keep things tidy...
When you actually fit the head unit to the van, make sure it is fitted securely and doesn't jump about/move when you drive along or go over bumps in the road etc...
That should be it, job done......
''COMMER'EnSayThat''