A/C not working

[Princess_Bishi]

A/C has not been working for a year. With my ‘17 SE being 5-6 years old now I figure the refrigerant is low. I bought some very basic supplies at O’Reilly’s (a can of R-134a without oil and a gauge for the low side) and the clutch won’t engage. I’m going to see if I can jump start the compressor from the fuse box with a paper clip so I can get an accurate pressure reading and add an oz. or two of refrigerant. Has anyone done this on the Mirage before? I’m nervous about doing this but I will report back whether or not it works.

[Princess_Bishi]

Also does anybody think when I jump it it might hurt the compressor shaft seal? I have heard they get dry and crusty when not operated in a while. What does replacing that entail?

[mohammad]

This obviously isnt the safest thing to do as you may set check engine codes as the computer was not expecting the pressure change. you can also theoritcally over pressurize the system the computer has sensors that will cutoff the compressor if pressure enters an unsafe range.

[Mark]

A/C has not been working for a year. With my ‘17 SE being 5-6 years old now I figure the refrigerant is low. I bought some very basic supplies at O’Reilly’s (a can of R-134a without oil and a gauge for the low side) and the clutch won’t engage. I’m going to see if I can jump start the compressor from the fuse box with a paper clip so I can get an accurate pressure reading and add an oz. or two of refrigerant. Has anyone done this on the Mirage before? I’m nervous about doing this but I will report back whether or not it works.

I like doing things myself, but I would hire someone to measure the refrigerant level. If it's low, I would have them test it for leaks next. If it's not low, I would want them to test whatever is next.

My local mechanics need to make a living, too. If I don't have the right tools or experience to do some things, I don't mind throwing a little money at them.

Some have way more experience with A/C. I don't like guessing about what the problem might be. I'd rather have someone confirm the problem & proceed from there.

I am not trying to discourage you, but guessing can become costly sometimes. Some else recently had refrigerant added to their 2017 G4. That fixed the problem at the moment, but it didn't really fix his original problem (a leak somewhere most likely).

Adding more oil doesn't fix bad piston rings either!

[Princess_Bishi]

I’m well aware that my capabilities are limited with my lack of a ~5000 dollar tool. I checked the relay and fuse, they were both good, then I tried jumping the compressor from the fuse box and the low pressure switch to no avail. I like to try things that are within my control so that if I have to go to a shop I have more information and hopefully won’t get ripped off. I’ve encountered bad technicians before so I am wary. But it’s going to a shop and hopefully they find something I couldn’t so I don’t have to have them replace the compressor clutch. Looking online them *******s are over $600. For just the clutch!!!

[Top_Fuel]

There have been some compressor clutch failures reported. Because of the pricing, it's pretty crazy to buy a $600 compressor clutch. You might as well get a good used compressor from the newest, low mileage car you can find. In other words...I wouldn't buy an AC compressor off of a 200K mile 2014 from Florida. eBay seems to be a good place to start looking.

Here are a couple of related threads to check out:

https://mirageforum.com/forum/showth...help-AC-Clutch
https://mirageforum.com/forum/showth...essor-fit-2014

If you hook up your low pressure gauge without the car running, does the system have any pressure right now? I'm just trying to see if you have a bad leak where all of the refrigerant has already leaked out.

[Princess_Bishi]

At the time I wrote that I did not even think of trying to find a used one… I believe there’s a Mirage at a junkyard around here and in Ohio you only use a/c for 3 months of summer and to defrost your windshield. The high and low side do have pressure. I think this weekend I’ll try jumping the compressor from my truck battery (I’m going to take the battery out of the truck) with the car turned off just to try the hear the click of the clutch engaging. It would also be good to go to O’Reilly’s and borrow a good gauge to get a good measurement of the pressure. And I will also read those posts you so kindly linked me to!

[7milesout]

If you purchase a can of refrigerant with a gauge and trigger, go ahead and connect it to the low side (engine off). It will read pressure. This can and pressure gauge is not the best solution, but in many cases it can be good enough.

If the reading is below their indicated good zone, squeeze the trigger.

You don't even need to be concerned about trying to bypass a sensor to engage the clutch to run the compressor. That it not necessary. Even if you bypass and get the clutch to engage, if the clutch is a problem and you bypass it, you've accomplished nothing but maybe add some refrigerant that you're going to lose anyway.

After the system has been shut off, pressures on both side of the fixed orifice or expansion valve equalize. I forget the numbers off hand but they settle out at maybe 75 to 80 psi. Let's say 80 psi. It could be lower, but I don't remember exactly. And this psi varies based on ambient temp, and probably some other factors.

If your system is off, and pressures in the system is at 80 psi, and the pressure in a new/full can is at say 250 psi (can't remember that either, could be higher, could be lower), the refrigerant is going to go in. At least to start with, for a burst at least. All of the above as I wrote it my intention is that the engine and A/C system is OFF.

And also, when you hook up the can and the gauge reads pressure. If the pressure is in the 80 psi range, and then let's say you watch the gauge while someone cranks the cars and activates the A/C system ... if the clutch doesn't engage at 80 psi, then yes, the trouble is in the compressor / clutch / sensor / A/C system, it is not a refrigerant (leak) issue. Disconnect the can and take your car to a mechanic. On the other hand, if the clutch/compressor does engage, the gauge should show a drop in pressure down to maybe 30 - 35 psi. At which point the 250 psi in the can is even easier to inject into the system.

The instructions on those cans are likely written very well, and should do a good job to improve the performance of the system (my guess).