My best guess would be the blower regulator. It is possible that the regulator quits due to problems with heat transfer and shuts itself. Either reinstall, use heat transfer paste and install to see what happens or change. Then again, on some models you can not buy these regulators and you have to change to another model and some modifications are required. Interesing to know if your AC's has any fault codes. See stickies under climate to get the fault codes and get the readings on sensors from 1-41 and post when car been runing after 10min. Even better, get the readings when your blower has failed to narrow down the other possibilites.
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