the aux fan only supplements the main fan. when the a/c is on, the condenser makes heat, and a lot of it. the extra fan only helps to cool the radiator and condenser. if your a/c isnt cold, you have a leak somewhere. get it checked, or if you've done the r-134 conversion, add some dye to it, and check it yourself. the kit for checking comes with dye and a u.v. light. cost is like 30 bucks, and worth it if you don't mind doing it yourself.