Why does A/C stop blowing cold after about 20 minutes?

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. Naturally, this concern requires hands-on, testing to determine what is going on. I can only give a guess. But I will tell you that one thing I have seen with these vehicles is that a pressure cut off switch can stay engaged and prevent the compressor from shutting off when it needs the cycle. This can allow the evaporator to freeze over. If this happens, you won't get cold air. You might not get any air at all or get limited air flow. If it is hot air, that is happening, intermittently, you could have an issue with the condenser fan, you could have a cycle switch issue, you could have a climate control system issue. It's all difficult to know until you perform testing. Reach out to a shop near you -- https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.