Hi, so I bought my tl back in April. Since I bought it the ac has blown hot. I ran self diagnostics on the hvac system and received code k for the mix motor. I removed the mix motor and repaired it and now have no more codes but the ac still is not blowing cold. So I decidced to try and charge the system. I pressed the schraeder valve on the low port and there was refrigerant/pressure in the system so I know I dont have any leaks. I hooked a can of refrigerant up and turned the ac to max and turned the car on, and it seems that the can of refrigerant still had the same amount ten minutes later. Like the system isnt sucking the refrigerantr in. Also the compressor wasnt kicking on at all. Any ideas? its pretty hot, especially with black leather.... compressor..... condenser...??? Any and all advice would be much apreciated!

 

You may have air in the system, which would prevent you from charging any refrigerant into the system. You'll have to take it to a shop with an A/C machine to have the system evacuated and then charged with refrigerant.

 

Even though there is pressure when I press the shcreader valve you think I still may have air in the system? Is there a way to check?

 

The pressure you have may in fact be air. If it is in fact refrigerant the pressure you release when you press the schrader valve should be cold. If it's warm then it's just air.

 

Lmao, um...what?

You can't charge the AC system because more than likely because the pressure inside the system (without the compressor on) is the same pressure as inside the can...equal pressures cannot exchange from one to another. That's not to say that your system isn't under or overcharged as of now. Charging is generally performed when the compressor is on (while monitoring gauges to determine correct charge) but can be done off if the system is off and the refrigerant is added by weight. Anyhow, there's a reason why your compressor isn't engaging and this is an issue not always detectedin the HVAC control heads self diagnostic feature. Starting at the compressor clutch relay (and AC turned on at the control head) find out if the relay is actually being energized or not. You should hear or feel the relay click when system is turned on. If it is, your issue exists on the load side and should be fairly easy to figure out (bad compressor, blown fuse, broken wire are most common). If the relay is NOT clicking, there can be MANY different reasons. Find out if the relay is engaging and then come back and give us a report.

 

Any idea where the relay is located so I can check to see if it is clicking?

 

I believe it's located in the engine compartment fuseblock. It's normally identified by the snowflake to indicate its relay position.

 

The compressor clutch relay is located in the engine compartment on the passenger side close to the firewall. Looking at the fuse block standing in front of the car, you will see 3 relays that run parallel with the length of the car on the right (your right) side of the fuse block. The relay closest to you (also closest to the front of the car) is the compressor clutch relay. Here, I will make a beautiful illustration for you not only to admire, but also use as a reference to locate the relay.

***illustration was removed due to how hideous of a design it turned out to be***

 

LOL. Thank you for being so informative, given your written description I should be able to now locate the relay. I got to get to sleep for work soon so I'll check it tomorrow. Ill be sure to post back with my findings. Thanks!

 

ok so I checked the relay labeled mg clutch relay in the under hood fuse box. There was no audible click heard and I held my hand on it and the was no click sensation.........

 

Just to be sure it's not just a bad relay, swap the said relay with one similar to its shape/size and terminal arrangement (on the bottom side) to see if it's just the relay. Also, be sure and check fuses...easiest things first.

Next, we need to determine what's missing here to not energize the relay. Obviously, all it requires to energize the coil is a simple power and ground. When you remove the relay, you will see four terminals on the bottom side...2 gold and 2 copper. With a volt meter, tell me what each terminal reads in the fuse block of where the GOLD terminals would plug into when reseated. It should read power, ground or nothing. Also, to ensure the AC compressor works, you can also jump the two contacts in the fuse block with a small looped wire of where the COPPER terminals would be if the relay were reseated. More over, tell me what the gold terminal placement terminals read.

***Be sure and do the above test with the AC on and blower motor on max***

 

Ok so I just went outside and I switched the ac clutch relay with the condenser fan relay and the ac clutch relay powered the condenser fan but the condenser fan relay did not power the ac clutch. I tried to jumper the 2 copper terminals but I did not hear the clutch kick on and the ac did not begin to cool. So i went and bought a multimeter but I'm not to electrical savvy so am not sure exactly how to use it but when I put the red end on one gold terminal, and the black end on the other gold terminal I got a reading of about 13.59....

 

By the way this is what the multimtere was set on when I got that reading. The little book it comes with says its for voltage range

 

Give 20 min, I'm driving

Btw, u have the setting on AC current. Switch to 12V batt and retest.

 

Ok just got back in, I switched it to 12v batt as you said. I turned car on, put ac on 60, and blower on max. I did as before and put red on a gold terminal and black on a gold terminal and I got a reading between 13.61-13.65. Thanks so much for taking the time to help me. Hopefully I can get this figured out eventually.

 

Okay, when I say gold terminals, I mean the one's on the bottom of the relay. Then, if you were to plug the relay back in, the terminal positioned (on the fuse block) in the same location as the gold terminals on the relay...lol, that's really hard to explain in words sorry. To clarify (just to be sure) there are 2 male gold terminals on the relay...the 2 females terminals on the fuse block in which the 2 gold terminals plug into are the ones to be testing. When checking for a power at the terminal, put the black lead on the negative battery terminal and the other on the point of which you're checking for voltage. And the opposite when checking for a ground: put the red lead of the volt meter on the positive battery post and then the other at the point of which you are checking for a ground. If at any time the meter reads battery (or close to) voltage, that means you have a power or ground. If that is too much, I'm sorry...try watching a clip on YouTube. :-)

Here's the deal: When the AC has been turned on, there should be a power on one terminal (this is present regardless if switch is off or on) and the other one should be a ground signal provided by the ECM if the ECM and HVAC control head detect no issues and also given they are good components. We need to find out what's missing here, the power or the ground.

 

Just thought of a way to simplify this. Find the AC pressure switch that's between the front bumper and the radiator...near the passenger headlight. Again, with the AC turned on, tell me if the blue with a red stripe wire (there's 2 and doesn't matter which one) and tell me if that wire has power. If not, does the yellow with a green stripe wire have power?

 

Ok, I get it now. I will do that after work tomorrow. You probaly think Im an idiot lol, I never have used a multimeter before so bear with me. When I was saying gold terminal I meant the female terminal that the gold male end(on the relay) connects to. Tomorrow I will get it done the rigth way and post back, even if I do need to study some youtube videos first lol. Well thanks again for your continued guidance, it is much appreciated!

 

Let me know. And an idiot is one who doesn't try to become better and is not afraid of learning something. We all start somewhere...

 

I will definetly check the preesure switch first thing as soon as I have a chance tommorow. Thanks again!

 

Ok. I just checked and the pressure switch is getting power and a ground, my fans also turned on and off when unpugging it. I also went back and checked the female terminals that the gold connectors plug into and one is getting power the other a ground as well.

 

Check the pressure sensor while it's plugged in. Don't disconnect it.

 

So, what's the verdict?

 

well I found this pretty useful...
12 years later.
I think my compressor is cooked at 246K miles...
probably time.