i push schrader valve by radiator support, no pressure. isn t this the high side? i put some UV dye in little transfer canister to introduce into ac system. no leaks but seems high preasure. i put gauges on and no pressure on either high or low side. hmmm . the gauges work. almost new. i have used them before. i can depress shrader valve by firewall. no preasure there either. GT 1 says recirculation malfumction 640002. i was mistaken on main cooling fan running. it is not. is there a way to jumper the sensor? i ran short test in INPA and gt1 55. any thoughts from amy memebers? wow cooling fan assembly. $524 . any good sources for this?