A/C not working properly

Sounds like one of two issues. First the compressor clutch is not engaging due to a clutch issue. Or this could be a relay/control module issue.

Let's start with finding out if you have an Auto A/C system with or without the Climatronic system? Or do you have a manual A/C system?

This is going to determine possible causes so we need to find out which you have.

However, we want to also find out if the clutch is engaging when this issue happens. So in the morning, start the vehicle and turn the A/C on and the look under the hood to find out if the compressor clutch is engaging. I am pretty sure that it is not.

Here are a couple guides that talk about this issue in general but I think you are going to have a control issue so let's find out about the info above:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

https://www.2carpros.com/articles/replace-air-conditioner-compressor

More than likely we are going to have to check the voltage at the compressor to find out if the control module is commanding the compressor on or not. If you want to go ahead and check this then I included the wiring diagram below and the location of the control valve on the compressor. Clearly if you have a different system then the wiring color could be different but it is still going to be a power and a ground. So just check the voltage across both wires. Meaning put your meter leads in both wires. If you have a negative number then they are just reversed but the actual voltage will be the same. So if you have 12 volts or -12 volts, it is still just 12 volts.

You should have 12 volts when the compressor is to be on so here is a guide that will help with testing this.

https://www.2carpros.com/articles/how-to-check-wiring

Please see below for the info that I am referring too and let us know what questions you have.

Thanks

Thank you.

So this car has an A/C switch and the climatronic where I can leave it on full auto and set the temperature, but yes I can turn the A/C on and off.

I will try and check the A/C clutch in the morning.

Are you able to tell me where the A/C relay is?

Okay. That is good info. It is not going to change how to test the voltage across the two wire connector at the back of the compressor but it does change the what in which it is controlled. This does not have an external relay. It only has the Climatronic control module which is what turns the compressor clutch on and off.

So if it is doesn't turn on then I suspect the control module is the issue. However, it is worth checking the voltage when the A/C is on but the compressor is not turning on first thing in the morning. If you have voltage then the compressor is the issue. If no voltage then the control module needs to be replaced.

Thanks. Let us know what you find.

Alright I will try and get that tested. Will the compressor in that car have a clutch?

We are not able to know for sure how this was equipped without running the options on it and I don't have the ability to do that. So I am attaching the info below on these compressors and how to replace them.

The way to tell if there is a clutch is to watch when it turns on if there is a plate in the front that is not spinning and then starts spinning when it engages.

However, if there is no plate then you could have a non magnetic clutch or even a fully electric compressor.

Please see the info below on this and let us know if you have questions. If you still are not sure, get a couple pictures of the compressor and we can go from there. Thanks

There is no plate that does not spin on this car. I will have time to test it tomorrow. Driving in to work today it did the usual behavior of A/C not working for several minutes. It almost seems like there needs to be enough heat for the A/C to engage. I do recall the other week when the car had been sitting in the sun (we are in PHX AZ) the A/C worked upon first start after a long period of not running. I can hear the system engage when I turn the switch on as well.. any ideas? I should finally have time to test the electric tomorrow morning.

Okay. Maybe I didn't understand that it will eventually start working after it warms up. I am thinking we should expand this search slightly by checking pressures just to make sure they are ok when the vehicle starts. In other words, let's check the pressure of the system after you let it sit. Then leave it on there and check as it warms up just to make sure they are correct until it finally turns on.

I am thinking we may have a pressure sensor issue that is preventing the compressor from coming on. Correct pressures will point to a sensor issue and the PCM is getting bad info.

Do you have a scan tool that can monitor the Climatronic module?

Is there one or two pressure sensors/switches on this? Where is the low side vs. high side? Those I could do on my own.

I am actually only able to see one pressure switch/sensor…

Correct. You only have a high pressure sensor. It is in the right front of the engine compartment. Below is a picture of the connector. I was trying to find the location but it does not give much info on it.

Great, I will try replacing that first. To confirm, there is a Schrader valve in there, so no refrigerant will leave the system correct?

That is correct. There should be a valve in there but just check the new one and make sure.

Below is a picture but I cannot confirm this is from a 2015 and the manual does not have a specific process for this sensor which also tells me that is because it is so easy. Just unscrew and install the new.