my air conditioner will not work and the sensor that detects the control is saying it is icy and cold when it is 80 degrees outside someone told me I needed to replace a relay switch any suggestions

I'm having the exact same problem! It started about 3 weeks ago. My AC is sometime cold, but most the time it blows hot air and the temp reading bounces around, saying its anywhere between 40 degrees to -40 degrees. Any input will be helpful. I have a 2013 equinox.

where is the location of relay switch? i also face problem but only when i wash my car AC stops working and about 7-8 hours later only it works