Surf auto 4-wheel drive

[Kathy]

Can anyone help, I have the similar problem to one previously posted, my 4-wheel drive on my 3 litre automatic surf, is not engaging, the light on the dashboard is flashing and won't go off. I'm told it's a wiring/switch/solenoid issue but I am finding no one can help as being an import the wiring is one colour. I took it for a diagnostic check but after checking they said they couldn't do it because of the wiring colour. Can anyone recommend somewhere in Scotland (as close to Inverness as possible) I can take my vehicle to get it sorted? The gearbox is fine otherwise.