Keninn, do I understand correctly that one possibility for the clutch not engaging is the push button/amp in the dash? As I stated earlier, we can dial in different temps and the fan speed blowing into the passenger compartment changes speeds. It doesn't get stuck at 77 degrees. But I don't hear any clutch kick in or idle up or any of that.

If this is accurate(that the amp could be the cause of the dead clutch), I'm thinking I might just change out the dash components(push buttons/amp assembly) with an Ebay purchase and see if that nails it. Worth a try?

 

certainly worth a try. i know the compressor is buried, but i would still first try to hotwire the clutch and see if it comes on and the liquid line gets cold. then you know the compressor/clutch is good. at any rate, a spare a/c amp is always good to have.

 

Do you think this one is compatible?
95-00#C969

It's on Ebay from a 1995 Millenia. The listing says it fits 95,96,97,98,99,00.

 

94-96 MAZDA MILLENIA CLIMATE CONTROL K79901TC OEM (ca4) | eBay

this is the one you need. up to and including 00 my. i cant see the one you have

why dont you check craig's list in your area, and look for one being parted out. they are the same for 2.3 and 2.5, and the 01 and later might even work, i dont know

 

Well I plugged in the Ebay dash unit(push buttons/amp) and it made no difference - compressor still is not kicking on. The new button unit seems to be working fine in that the temp changes when you change the dial, but the old one was fine in that regard too.

I think I'm going to put it in the shop(not the Mazda dealer rapist) and hope that it just needs freon or a relay that they can figure out without me needing a second mortgage.

 

Probably will end up in the shop anyway, but I'm still plunking around with this climate control. As stated in earlier post today, the dash module I bought on Ebay did not do the trick.

I downloaded the manual for the 2000 Millenia. Flow chart #19 covers the following symptom - "Magnetic clutch, condenser fan, and A/C compressor idle-up do not operate." This is my situation. First step is to check continuity on the pressure switch - I did and I don't have any.

Due to the freon concern, I guess I'll put it in the shop and ask the guys to do a new switch and new freon.

 

If your A/C is not working and your A/C compressor doesn't turn on, learned a trick today to check for probable low freon. Disconnect the plug from the A/C pressure switch, start the car and turn the climate control dial to 65 or a low enough temp to force the cooling on, then use a paperclip to jump across the terminals on the pressure switch plug(not the switch itself). If the compressor kicks on you probably have low freon. Don't let the compressor run very long.

In my case, the compressor did kick on so it's going to the shop tomorrow for a charge.

 

the bad thing about that is there is a leak somewhere. could be big, could be small. since the system is sealed, it will leak out again. if the leak is small, there are some excellent products out there that will seal the leak

 

Yes, I understand. I figure I'm due for some good news! After I get the A/C fixed and the P0421 addressed, we'll probably sell this thing. It will probably be less expensive for us to help him buy a better car than to keep pouring cash into this thing.

I always though I'd like a Miata for a weekend cruising convertible. This is the last Mazda I will have be associated with - and my family too.

 

Did you get this fixed? I have same problem and know the freon pressure system is good so an electronic problem. I have worked on it quite a bit and can help you with some of the diagnosing.
Mine is not fixed yet as can't seem to find how to get the PCM (Powertrain control module) out. The PCM is one of the units in the circuit.
Anybody else out there been able to diagnose through the PCM and the AC amplifier module?
Anyone know what all sensors have to be good to get AC to come on?