# Mazda A/C Mystery **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [July 8, 2011, 8:34pm UTC](https://community.cartalk.com/t/mazda-a-c-mystery/66067 "2011-07-08T20:34:16Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![gnewall](https://avatars.discourse-cdn.com/v4/letter/g/bc8723/32.png) [@gnewall](https://community.cartalk.com/u/gnewall)\ **Post date:** [July 8, 2011, 8:34pm UTC](https://community.cartalk.com/t/mazda-a-c-mystery/66067/1 "2011-07-08T20:34:16Z")
Had my 97 Mazda Protege’s A/C diagnosed today, since I get no cool air at all. Interestingly, freon is plentiful, compressor and condensor are in great shape, no leaks in any hoses. However, mechanic says there is a problem with the A/C Amplifier/the thermo-switch is not providing a ground signal. He also said its something between the evaporator core and the blower motor. If anyone can help, it would be great. P.S. the blower motor resistor is fine - I can get hot air at several different levels. ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [July 8, 2011, 10:20pm UTC](https://community.cartalk.com/t/mazda-a-c-mystery/66067/2 "2011-07-08T22:20:33Z")
So, you’re saying the mechanic can diagnose it, but can’t fix it? If that’s the case, find a better mechanic or take the car to a shop that specializes in automotive HVAC systems. They’re not that hard to find. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [July 9, 2011, 8:56pm UTC](https://community.cartalk.com/t/mazda-a-c-mystery/66067/3 "2011-07-09T20:56:31Z")
The AC amplifier is in the cars computer (ECM). It provides ground to the compressor clutch relay (therm-switch?) Start with the relay.