it's should just be;
power and ground to the black box,
and a power lead to the display
it should be pretty simple, unless the display lead is routed through the engine bulkhead.
but if you are uncomfortable, don't risk frying your system. i would pay no more than $50 USD to have it installed. I am assuming you are in England based on the way you spell tire(tyres). But I don't know the market value of the install there. You should pay less than having a radio installed. And if they calibrate it, you should pay the same as a radio install. Unless they go through the bulkhead. Then it will be a little more.
Hope that helps.
Last edited by dvmotorsports; 01-12-2008 at 04:36 PM.