Range Rover air conditioning with climate control - help

Hi all you Range Rover owners, is there anyone out there that can provide me with a wiring diagram for the air conditioning sytem on a Range Rover - model year 1999? I am trying to identify an intermittant problem with the air conditioning system, the vehicle is fully gassed up, but only works when it feels like it. Any ideas? A pdf file of the wiring system would be nice.

Cheers,

Drive Cool.