I have 2 2nd gens and both have the same problem with the a/c. The a/c fan stops blowing when I get up to around 60. Anyone have any idea what this could be? I need to put Freon in one, it’s summer and I’m tired of burning up, and 90% of my driving is on the highway.

 

Are you sure it's not just reverting back to the defrost position? If you loose vacuum it will do this.