In for repair this week was a Jaguar S-type with no cold air from one side of the dual climate control system.
As some work had previously been done to this vehicle by the owner which included replacing the dual climate control valve and the climate control module to no avail this really only left the wiring to be the cause of the fault.
The Brown and White wire to the control valve was found to be open circuit. After stripping back the insulation around the wiring harness at the bottom of the radiator a break was identified. Wire repaired = Cold air from both sides of heater = Happy customer.