no a/c, air always warm? 3vzfe - Toyota Nation Forum : Toyota Car and Truck Forums

12340987 · 06-09-2010, 03:22 PM

I'm fine with the windows down, but on long trips the a/c is good to have.
But even with the a/c off it keeps blowing in hot air though, even if the outside temp is around 60, the vents will bring in warm air.

I looked up expansion valve but these symptoms don't seem to match up.

Also, the a/c compressor doesn't come on. I replaced the relay, which looked burned out but turned out not to be, and still nothing. When I manually short the relay I hear a whirring noise (not like a compressor should be), but there is no cold air from the vents. I also do not read any voltage from the terminals at the compressor relay.

The green light on the a/c button does come on. This is in a 93 es300, which I assume is the same except for the some of the electronics.

dave1811 · 06-09-2010, 05:59 PM

What are the pressure readings and at what temperature? I am assuming you have plenty of either R-12 or R134A in the system?

12340987 · 06-09-2010, 11:52 PM

Eh? Does that really matter if the compressor isn't even coming on? No clue about that, don't even have the tools to measure it.

Maybe my post is a little unclear, the compressor doesn't come on at all unless I push the electrodes of the relay together. It doesn't seem to be producing a signal to turn on the compressor.

***fenixus*** · 06-10-2010, 12:26 AM

so the relay is stuck ? have you tried knocking on it to see if it helps it click (on running car and a/c turned on) ?

12340987 · 06-10-2010, 12:51 AM

It's not stuck, it doesn't come on at all. Should I be seeing 12V at the relay signal terminals, because I don't.

Stillrunning · 06-10-2010, 06:43 AM

Quote:

Originally Posted by 12340987

Eh? Does that really matter if the compressor isn't even coming on? No clue about that, don't even have the tools to measure it.

Yes it does matter and basic tools for A/C is minimum requirement. I don't have electrical diagram for your vehicle but which relay are you referring to, the compressor clutch relay, fan relay? If there is insufficient pressure in the system the pressure switch may not be allowing the compressor clutch to activate, or the fans for that matter. Have you tried jumping the compressor clutch with 12v to see if you can it to engage?

12340987 · 06-10-2010, 07:00 PM

Ah, most wise, stillrunning. Is that because it contains lubricant?
I just found the FSM for the a/c system and did a diagnostic, threw error 43 and 22

pressure and air mix damper.
Explains why it blows warm all the time when its on vent. Anybody ever dealt with the air mix damper before?