Recently, I found my air conditioning blowing cold, then warm air. I made an appointment at the Subaru dealership, but I was scheduled out for two weeks. Here, in Maryland, we have already experienced temperatures well into the 80s. I researched on YouTube, and I found a quick fix. Under the roof, located to the right in the fuse box, seek the blue, rectangular fuse. It is the AC relay. Tap it with a screwdriver or wrench (with the car running). The compressor should immediately click in. Boom! Success. Cold air. However, I took it a step further. For $13.99 at my dealership, I purchased a brand new AC relay. I made sure the car was turned off. I used a pair of pliers to pull the old relay, and replaced with a new one. That's it! I now have stable air temperature.