In driving my 2004 Toyota Highlander, fan blows hot and then cold on “cold” setting. Just hit 85,000 miles. Thermostat?
Nope, not thermostat. The thermostat maintains the engine temp not the cockpit. If the air is not cold when the AC is on, you could need a recharge due to a leak in the AC system. Best to have a pro look at it.
2 questions to better answer yours… …first, when you say hot, is it hot like the heater is on, or just warm un cooled air. And when it starts to blow cold, does it keep blowing nice ac cooled air? If it feels like the heat is on then switches to ac then I would say your blend door is sticking, and not moving fast enough to cold. Or stuck half way.