First hot summer day and my AC blowing warm air...

Took this car to a Canadian Tire mechanic, he looked at it, told me it's AC relay not clicking and not turning the AC. They did not have the relay so I took the car back, took relay out.
It's Siemens 12V relay that shows the circuit on the casing. Attached it to 12V power supply and it's clicking...
So relay is fine, but what could that be? A switch on the panel? Maybe not.
Searched this forum, it seems some people fixed it by cleaning contacts of Electronic Control Module that sits in the box beside windshield washer fluid.
Took it out, cleaned it with rubbing alcohol, let it dry, put it back. AC switch light not working, took out the relay, put it back in, and voila! You can even hear AC clutch clicking with a puch of a button.

Which makes me think - if it was the contact, why the problem was with the AC and not with other contacts - this ECM controls everything, right. Maybe ECM just needed a reset. Anyways I'm glad it fixed the problem, hopefully somebody else will fix it the same way.