Last weekend have found out how to switch on the nav sat.
With the fobs installed and without pressing the brake pedal, if you then press and hold the start button for about 3 sec then the ignition lights on the dash come on and the nat sav is also on.

To only switch on the nav sat insert the fobs and press the start button briefly then the nav sat comes on but not the ignition lights.

does that mean you have got the sat nav working

(it was you who was having problems wasn't it)  Former Mod/Member, with the most post & Chicken George Arch nemesis

Yes the sat nav is then working and you can input your routes and waypoints etc. without the ignition lights on.