A/C Went Out, how to diagnose?

[Oriah]

Good morning everyone. I have an older 2013 S (no longer understand warranty) and my AC went out just today. I have called Tesla and went through a bunch of reset procedures and it looks as though it's a hardware/mechanical issue. They advised I make a service appointment.

I have been reading up on the causes and it seems that at minimum I'm looking at a 4k repair, which I'm simply NOT willing to pay. That being said it seems like there are only a few reasons why it could go out.

1) low freon (which I've ruled out)
2) bad compressor
3) fuse popped in the DC to DC converter.

My question is simple... How can I rule out what the problem is? I want to try and fix it myself and I'd rather figure it out without dismantling the whole car.

Any help would be appreciated.

 

[Knightowl]

Good morning everyone. I have an older 2013 S (no longer understand warranty) and my AC went out just today. I have called Tesla and went through a bunch of reset procedures and it looks as though it's a hardware/mechanical issue. They advised I make a service appointment.

I have been reading up on the causes and it seems that at minimum I'm looking at a 4k repair, which I'm simply NOT willing to pay. That being said it seems like there are only a few reasons why it could go out.

1) low freon (which I've ruled out)
2) bad compressor
3) fuse popped in the DC to DC converter.

My question is simple... How can I rule out what the problem is? I want to try and fix it myself and I'd rather figure it out without dismantling the whole car.

Any help would be appreciated.

Sorry, same issue here with my Oct 2013 build. I think in my case the compressor is toast. Very annoying since it happend less than 5k after the full 50k maintenance I had them do and asked specifically for them to look into an AC thudding sound I had been having intermittently. I have an appt scheduled 2/15 hoping same day as it is the primary kid hauler with the extra rear facing seats.

 

[Oriah]

How can we diagnose between the AC compressor and the DC to DC converter?

 

[Dithermaster]

DC-DC converter seems to be one of the most common reasons for A/C to fail. It would be nice if it popped a diagnostic message.

 

[PWlakewood]

I was told that I needed to replace my ac compressor and dc/dc converter when the ac stopped working in my 2013 S. I asked for a second opinion from a different tech and he came back and said the freon was low so it shut down the compressor. My bill went from $3400 down to $85 and everything has been working great since. You mentioned that you ruled out the refrigerant being the culprit, how exactly did you go about this? The refill kits with the gauge are pretty inexpensive and if you havent tried this I would suggest it.

 

[Oriah]

I was told that I needed to replace my ac compressor and dc/dc converter when the ac stopped working in my 2013 S. I asked for a second opinion from a different tech and he came back and said the freon was low so it shut down the compressor. My bill went from $3400 down to $85 and everything has been working great since. You mentioned that you ruled out the refrigerant being the culprit, how exactly did you go about this? The refill kits with the gauge are pretty inexpensive and if you havent tried this I would suggest it.

I'll run to AutoZone now and double check but a few days ago it was cold outside so I blasted the heat. Later in the day it warmed up and so I went to turn on the AC and it just stopped working. I called Tesla and they told me that the car tripped an error cold saying something to the tune of that the AC stopped working. I think that maybe when I blasted the heat I blew a fuse and it killed the AC... Is that feasible?

 

[PWlakewood]

I'll run to AutoZone now and double check but a few days ago it was cold outside so I blasted the heat. Later in the day it warmed up and so I went to turn on the AC and it just stopped working. I called Tesla and they told me that the car tripped an error cold saying something to the tune of that the AC stopped working. I think that maybe when I blasted the heat I blew a fuse and it killed the AC... Is that feasible?

Same bs they told me. Go grab a refill kit and update us afterwards. No the fuse blowing by turning it on or off does not seem like the issue as they are designed to handle the current draw.

 

[Oriah]

Same bs they told me. Go grab a refill kit and update us afterwards. No the fuse blowing by turning it on or off does not seem like the issue as they are designed to handle the current draw.

I can use any refill kit no problem?

 

[PWlakewood]

I can use any refill kit no problem?

R134a. It will say on the sticker under the hood and as you are in Miami it should be a US model S.

 

[Oriah]

R134a. It will say on the sticker under the hood and as you are in Miami it should be a US model S.

Looks like I'm at 60lbs.... So there goes that idea

 

[ucmndd]

Looks like I'm at 60lbs.... So there goes that idea

So you've ruled out the easiest option, now you probably need to move on to the next one and replace the fuses.

Given the experience of others, and the fact that from your report the failure seemed abrupt but not catastrophic (i.e. the system is still holding pressure, no loud noises or bangs or other audible indications of a physically failing compressor), I think you have a very good chance that's the issue. $20 in parts and some blood sweat and tears on your part is a reasonable next step if you're not willing to give Tesla the $4k to just replace it all.

 

[Oriah]

So you've ruled out the easiest option, now you probably need to move on to the next one and replace the fuses.

Given the experience of others, and the fact that from your report the failure seemed abrupt but not catastrophic (i.e. the system is still holding pressure, no loud noises or bangs or other audible indications of a physically failing compressor), I think you have a very good chance that's the issue. $20 in parts and some blood sweat and tears on your part is a reasonable next step if you're not willing to give Tesla the $4k to just replace it all.

That seems the case. I know a great mechanic that works on BMWs and he's agreed to try and tackle the problem with me this weekend..I've ordered the fuses and I'll go to his shop and we can do it together. He wants to learn Tesla's and so this is a good excuse for him to grow his business

 

[PWlakewood]

Looks like I'm at 60lbs.... So there goes that idea

Are you testing on the low or high side? 60 is too high!

 

[Oriah]

Are you testing on the low or high side? 60 is too high!

I was testing for it on the low side. Would it being to high potentially shut off the compressor?

 

[PWlakewood]

I was testing for it on the low side. Would it being to high potentially shut off the compressor?

Yes it could cause a fault. Have you ever had it filled before?

 

[Oriah]

Yes it could cause a fault. Have you ever had it filled before?

No never had it filled. I will drain it to a proper pressure but I don't think that's the issue

 

[TMeister]

Ok, hold on a bit here. To test the pressures in an A/C system you have to have the compressor running. Was that the case? If you just connect to the low side port you will measure the vapor pressure of the gas at ambient temperature. In your case 60 psi of R134a is about 64 degrees F. What was your ambient temp?

if there is any liquid in the system, this pressure will maintain itself until you exhaust the liquid. So don't just bleed off pressure without the compressor running.

What you need to do is connect your pressure gauge to the low side port. If you read 60 psi then the compressor is not inhibited to start. Start the compressor. Do you hear it? If not, you have a bad compressor or control circuitry. Observe the pressure going down. If the pressure goes below the low side cutoff you are low on R134a (it's not called freon, that is the name for R22). The correct control algorithm is to modulate the compressor based on the temperature of the evaporator. The low side and high side cutoff switches are protection mechanisms.

 

[terryna]

Are you testing on the low or high side? 60 is too high!

same question

 

[MP3Mike]

Are you testing on the low or high side? 60 is too high!

60 isn't too high, depending on the ambient temperature, if the system is not running. And we know his system isn't running...

 

[Oriah]

I would say the ambient temp was about mid 60s, as it was a cold day in Miami. AC compressor was not running... I think maybe I'll take it to an AC guy, seems like I'm not knowledgeable enough to know how to properly diagnose...