Same route every day, same time around 3pm, same speed, around 55 mph, same mundane gentle crest in my lane that makes the car squat ever so slightly as I cross it.

It's HOT here in Houston already, so the a/c was on full blast, cross the little crest/dropoff (aka big tree root under the road pushing it up), then complete silence, instantly the air turns stale and hot, the blower is completely off. Initially I thought maybe it was the blower coil/relay box, but the blower was off in any speed. The compressor is still turning and a/c air is barely wafting out just from moving but the blower is definitely off.

Needless to say the rest of my drive home was completely miserable, but my question is, where do you suggest I start looking?