Air con problem?

Quite a while ago now I had the old notebook symbol come up on the old 98 Rangee and after taking it in to a guy I know for a standard service and mentioning that the A/C wasn't working he suggested re-gassing the system, which we did and sure enough the notebook dissapeared and the A/C was awesome for about a week!:beer2: , then the symbol came back again!. One thing I have noticed is that the temperature does not differentiate between passenger and drivers sides like it used to?.
I feel quite inclined to leave it in a way (just knowing how much these things can cost) but the notebook symbol has gone now but the A/C is not working and I wondered if it was possible to do any damage to the engine (as I know it can in some vehicles)?.

Any info on what the problem could be or fault finding would be good.

Get the gas level checked, you may have a leak and the Condenser (Aircon "Radiator") behind the grille is a favourite culprit. I have had 2 new ones in 6 years due to a pin hole in the top l.h. corner-looking at it from the front. New condenser is around £90 from Egay, plus of course cost of a regass.
Question is how much do you need the aircon on this weather!

Classic sign of low gas is that the compressor clutch will not cut in and out.

if there is a hole in the condensor, as in mine, get some of that liquid metal stuff. there is a type that is safe for aircon, and patch it up. mine is holding pressure fine so it's saved me a few bob on a new one!!