I bypassed this valve because mine is broken off the plastic parts. I have AC but rarely use it. I never noticed much difference. But I don't think this is for AC, The ac unit sends an electric signal to that valve along the right fender I think..I'll have to look up the manual again on this,,,I was going to make a replacement pipe fitting up out of brass or copper or metal and weld it up to the base. I think this valve is stupid expensive.