Cockpits were clickable, now they're not, what have I done?

[Chivas]

Clickable cockpit has never worked for me. I see the Mouse Control in the Options/Controls/key/Mouse Control has nothing assigned to it. I tried assigning my left mouse button but nothing appears, when I try assigning another key on my keyboard it works, but I have press that key aswell as move the mouse to move switches etc.

I don't know why this is. Can anyone tell me if the Left Mouse button the default key for Mouse Control?????? If thats the case I will continue to find out why it won't assign.