This has been an intermittent problem for the past couple of months. The ac blower wouldn't turn on at all until I got up to highway speed. Then it started working. But, whenever I'd turn, it would shut off. Fast forward a day or so and it's all good.

I'm going to inspect the motor and wiring this evening, but any other ideas?

 

there might be something stuck in the fan. Otherwise its a loose wire.