Hi there!

I have a similar issue as another person who posted. I have a 2003 Toyota Corolla that we have filled up with refrigerant a couple of times and the compressor will not kick on - thus no cold air.
About a year and a half ago the same thing happened but we were able to refill the refrigerant and it worked until about 6 months ago.

Now nothing seems to help. But the main thing is that the compressor doesn't kick on at all. It just blows lukewarm to hot air. It's OK on a day where it's like 50-60 degrees, but at soon as it hits 65 degrees it hot and awful. And here comes summer!

And sometimes when it it cold outside and I've got the heat on, if I'm in traffic and not moving for an extended amount of time it starts blowing cold air. :confused:
When it does that I have to put my car in the lowest gear and stomp on it for the warm air to come back.
I know - sounds crazy. No one I have talked to has any idea what is really going on. But I don't have any friends who are professional car mechanics. My husband is pretty mechanically inclined and usually fixes his own stuff, and my Dad is an aircraft mechanic.

I've done some research, and I think that it may be some kind of a relay issue? I've seen that word pop up here and there. But I don't have any idea how to order that particular part.

I think I just need to take it to the shop - but I don't want to spend a fortune at a shop if it's a relatively simple fix that I haven't heard of.
Or if they are going to piddle around with it trying to figure out the problem for forever because I need the car for work.

Anyone have any idea?

Thanks!

Let me guess. You have no idea of system pressures. You have never evacuated the system? You haven't checked the refrigerent safety switch? You've never caused the system to run and look at the pressures.

Initially I suspect a leak. I also suspect there are some non-condeseables (water) in the system. Water can do a lot of damage.

DIY - I doubt it.

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And sometimes when it it cold outside and I've got the heat on, if I'm in traffic and not moving for an extended amount of time it starts blowing cold air.

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This sounds like 1/2 of the outdoor air damper is opening. I'm comparing it to an older toyota and how it's system worked. Half of the fresh air damper is controlled by the AC system. This prevents freezeing of the evaporator.

You are correct! I have no idea about pressure. I know that by looking you can't tell that there is a leak. Of course that means nothing. I know we have also tried using refrigerant that is supposed to stop leaks. I have no idea how dependable that would be either.

I'm not sure what you have to do to evacuate the system, but I know my Dad released an earlier batch of refrigerant we had tried and then refilled with the non-leak refrigerant until it was full. Still nothing.
We had the car running and tried turning the AC on and off to see if there were any changes... nothing. A small RPM jump or hard idle, but the Compressor did nothing.


I don't know how to check and see if there is any water in the system. How would I go about checking for that?

In the meantime, I'll look into your suggestions and see if they help.

And for the heat issue - if the damper is only opening halfway because it is partially controlled by the AC System then the two problems are indeed related? (Which I thought... )
In other words, if I fix the A/C the heat should follow suit or would I have to fix something else? (in theory at least.)

Thank you!

It's more like the RECIRCULATE button. When you control it, the entire door opens, when the AC controls it, only half of it opens.

The AC can be turned on in defrost mode. Toyota made that separate.

Water is tough, but the system needs to be conneced to a vacuum pump and pulled to 10 microns or less before charging. Dry Nitrogen gas can be used to help remove water vapor from an open system. Fingerprints are deadly and so is water vapor.

I did a Toyota AC install from a box back in 83.

Tell your husband to get down on his knees!! Literally.
The large opening below the front bumper has an area to collect air and cool the condenser and radiator.
Look through there and look for any oily spots on the condenser. Small stones from the road can damage it and penatrate causing a leak in the A/C system.
As for heat, make sure the radiator hasn't been damaged also causing coolant loss. Low coolant will cause brief heat then cool air.
The relay is located in the engine compartment fuse block. Labeled 'Mag clutch'.
He can try and swap it with another one in that block if it has the same part number on it.