My air con is not working. It’s been re-gassed even though I knew it wasn’t the issue. 
I get some cool air while driving but once I’m stationary it blows warm. It doesn’t seem to be blowing with any force either, I have to turn it up to max to get any decent stream of air. Also, the warning light for over heating engine comes on, but plenty of coolant. 
Any ideas so I can be prepared when I go back to mechanic 

Is it a "climate control" system or a basic "on/off" aircon chiller?

 

Either way it sounds like you have a slipping belt. I'm guessing the same belt drives the water pump and the aircon compressor.

 

It may also be that you have a failing water pump, and as the car engine (and coolant) gets hot, the aircon can no longer overcome the heat.

 

By the way, if you lose refrigerant and thus need "re-gassing", don't bother unless you can identify why the original gas escaped. Or else you are just refilling a leaking bucket. You may get a very gradual loss of refrigerant over time anyway through various seals, but if it happens in a short period of time, there is a hole somewhere!

 

Edited 6 August, 20205 yr by freemansteve

Thank you for your reply.. 

it’s a basic on/off system. I had it regassed last summer so was pretty sure that was not the issue...but let myself get talked into doing it again! 
of course we are heading into a heatwave so I’ll struggle to book car in anywhere but want to avoid more wasted work 

Your aircon system must have a leak that needs fixing again, if it's only 12months or so since regassing. Probably the 'condenser' (a small radiator) or a seal on the compressor. Being a simple on/off chiller rules out a possible fault with climate control electronics (there are none).

 

I can't see how a possible lack of gas in the A/C is related to the overheating engine problem though - my guess above was based on the A/C having gas, but not cooling, and a simultaneous engine overheating.