Steering wheel control help

My adapter arrived today and and IVE plugged it in I think and it's not working with the controls on my wheel, the only positive is that it's had incorporated switchable power, any help?

There should be a cable that looks like a 3.5mm headphone jack on the adapter.
This needs to go into the back of the head unit, if it has the correct input hole for this function. Can you provide a picture of the adapter and the rear of the head unit?