Cool air on the right - not on the left (grrr)

Is it the manual A/c or climate? If it's manual then it's likely that the bowden cable has popped of it's clip. If it's climate then the servo may be poorly.

Does anybody have any comments on me trying my second hand unit? ie: could i blow some fuses or do some other form of damage...?

Can't see trying a secondhand unit doing any harm. Are you getting the flashing lights on the contol unit? Can you hear the temperature adjusting flaps move when you move the drivers and passengers temperature contols? Best to try it when the engine isn't running ign key at pos I.

Hi Chris, yes there is a definite clicking sound when the warm air comes out! I cant believe i forgot to mention this. This sounds like it may not be the control unit after all then...! Can someone point me in the right direction in locating and diagnosing this device/equip?

If you can hear 'clicking' then it would suggest that the ECU is trying to move the temperature contol damper motors. If you remove the trim etc. from the passengers side under the dash you should be able to locate the damper motor by moving the temperature control and locating the source of the clicking. You can then remove the correct motor. My expectation is that teeth on the motor drive are broken. Haynes manual 3573 for the V70 has a reasonable section on the ECC so I'd suggest getting one will help.

At long last