The AC is on. Set at 61 deg. Keeps going back up to 81 deg. Blows cold for only 3 min. Any ideas?

Did you replace orifice tube?

needs more freon

Dear Mahesh

In Cool Mode

Temp Diff - + - 1 deg C in Room Temp & Set Temp

This is auto cut

In Dry Mode

Comp Runs for 10 mins then get off for 5 mins then again get on for 10 mins this cycle continuues.

if the ac system is very strong and there a lot moisture in the air the a'c evaporator core will freeze up and stop air flow threw the cold core only use the recuiculation part to cool the car down about 5-10 min the turn the recuit off

i think its something to do with the computer controlling teh AC it does have one behind the centre console but what is wrong and how to do i have no idea to be honest ,this computer is controling the flaps on the heater unit that i do know as its a similar system to my jag ,best advice i can give is to back car to merc dealer and hope your credit card can stand the knock ,or trade it in for a nice small new car with a diesel engine

you may have a dirty condensor coil its the coil near where the warm air blows out or maybe a dirty evaporator coil its where the air gets sucked in check both of them and then see whats the air temp going into the evaporator and the temp. coming out of the vents that blow cold air the diffrence should be about 15 - 20 deg f let me know what the temps are ...but first clean the filter and both coils

either going off on low charge which would cause it to ice up, which means you need refrigerant. or high head pressure might just have to clean the coils or check condensor fan.

You did great! Yes you have a heating system error not a thermostat issue. The 2 blinking lights is an indication something is wrong. Now what you need to do is to remove one of the panels on the heating system and look for a wiring diagram pasted on the reverse. On this diagram there will be a diagnostic chart explaining where to start looking for an issue based on 2 blinks. Because each model is different, a 2 blink error code could indicate a bad pressure switch, plugged air filter or any other thing.

Replace the temp control on this car, it should be electrical control not cables.

Oh, the compressor motor's borked or overworked and overheating, or its capacitor failed short (perhaps the motor is shutting off from thermal shutdown...but you get to find out whether that's so. Be safe.) Alternately the temperature sensors have gone touchy on you. Once you gently vacuum it clean, try keeping incandecent bulbs in series with the compressor to get an idea of how loaded that thing is as it runs for those 5 minutes or so; the load might change more than you expect, just pay attention.
Hopefully you won't have to replace the compressor or motor; but it's doable if you're a certified technician with like equipment (so you can handle the refrigerant decently.) Most shops will streamline a bunch of similar jobs together to cut the waste and setup time.
Bigger conditioners are so much more efficient than little ones...syndicate the A/C?