A/C Troubleshooting help needed! :)

[Israar]

Hey guys and gals!

Since having the FR from my brother, I've known he's not used A/C since having it so I don't know anything concerning it's history before my brother had this car!

All I know is that it's not worked or cooled the air since I've had it (I don't think my brother has even used it if I'm honest or tried it) and I have purchased the Carista App and connector a while back.

I've had a couple of faults come up and one as I assumed it would was the A/C.

The one specific to A/C is this:

Heater & air conditioning
Part #: 5P0907044P
Component: Climatronic
Coding: 0000000002 (hex)
Fault codes:
9481200 Manufacturer-specific code

I've searched on here and on google and found a few things but nothing that's jumped out at me, bare in mind I know absolutely nothing concerning A/C other than it's supposed to be bloody cold!

Anything, I went to Halfords today and purchased the EZ Chill Refrigerant and Re-usable nozzle as well as an Autoglym A/C cleaner (not used).

Did as the instructions told me, albeit when I tested the PSI it was on 0. Though ignoring the warning about not attempting to put any refrigerant in, I tapped the trigger to see if it would do anything. The pressure went up and was around 25 PSI.

I pressed for a couple of seconds and it slowly went up after releasing, got it to about 35 PSI in the end, albeit when I was done it was still blowing hot air. I had tried with the recirculation on and off (I read on here somewhere that for A/C to work it had to have recirc ON also? I may be incorrect though that's why I tried with it on and off).

I also reset the codes, not checked to see if it's back but given that the A/C still is blowing hot air I'd safely say it will come back if I put Carista back in?

What would be my options here? Would I be better off getting help from someone from here/local to scan with VAGCOM to get a truer reading of what's going on to see where my problem lies or what?

I really want my A/C running as it should and at present it's not doing what it should. I've seen suggestions about N80 and N115 (no idea what these are) the compressor,the pressure switch or fuses? Again I know absolutely nothing on this area at all... So besides wanting to learn more about it I don't even know where to begin haha!

Hopefully one of you wonderful bunch of people have had this problem and sorted it or know what dribble I'm on about haha!

--Lee

 

[iDan]

I am also in the middle of sorting my A/C problem too. Mine doesn't blow cold either.

I started by getting it pressure tested and re-gassed. Its holding pressure as it should do, suggesting that there isn't a leak anywhere in the system.

I noticed that you cant hear the compressor turn on, or any of the fans start when i turn it on and i noticed that the revs didn't change. (In my old car, when i turned a/c on, the revs went up slightly on tick over, i think powering the compressor?)

I suspect that either the compressor has gone, or that there is no power going to it. My next step is to check that there is power going to the compressor using an electrical tester on the plug and if there is power, i will replace the compressor. If that still doesn't sort it i'm not sure where to look next, so fingers crossed.

Do the revs go up on your car, or can you hear the compressor running when you turn it off and listen under the bonnet?

 

[Israar]

Hi iDan!

Thanks for the reply mate, looks like we're both in logger heads at present!

I'll check later at work to see if the re-gas I did has kept the pressure to make sure that there are no leaks, it didn't look like it was loosing pressure when I'd gassed it though.

I have never used A/C on a car before so never knew what to look out for or anything of the like, besides never owning a car before this that had A/C haha!

As for knowing what's what with what has caused this not to blow cold I'm lost at present, not sure how or what to test like you stated there mate. I don't recall the revs going up not hearing any noise of fans, though I can check that when I get to work tonight as I can get my friend to listen as to whether the compressor kicks in or not, truthfully I don't think it has kicked in? I'm sure I read with the error code I have with it showing up it wouldn't start the compressor? Albeit I can't quote myself on that

I also read about blockages in the pipes? If it isn't your compressor it might be that? Who know's I don't!

How are you going to electrically test the compressor?

--Lee

 

[iDan]

I'll just use a normal multimeter like you would use if you were checking for power in a house or socket/switch.

It could turn out to be an expensive game of cat and mouse sorting A/C, so I've been told.

 

[Israar]

Cheers Dan!

You'll have to keep me posted on how you get on mate, also if I'm completely honest I've used a multimeter once and that was aeons ago haha! I have one but if I was to use it I wouldn't know where to start as I'm not sure on the voltages and such concerning checking things in the car.

From what I remember you have to select a current that's higher than you need to check, aside from that I'm air headed! XD

I checked this morning after work to see if the gas charge was the same as what I put in, and it was just below 25 PSI so going from that I have a leak, I'm nipping out shortly so will check again to see if the charge I put in this morning has kept, if not I'll have to get it leak checked...

Yeah I can believe it too with the wide variety of things that can go wrong! :O

--Lee

 

[Israar]

Hey iDan, have you managed to get anywhere at all with checking the plug that goes in to the Compressor mate?

I'm at that point now, I took a trip to Climate Control in Birmingham and they said the gas was low, they filled it up properly and mentioned that to eliminate the Compressor get the relay checked. He said it should show about 9V?

I'm not 100% sure what voltages I need to be seeing so any tips would be really nice!

I hope yours isn't your Compressor as they look expensive to replace!

--Lee

 

[iDan]

Hi Lee
If I'm honest I haven't got round to it yet! I've been busy with work and personal life.
If all goes to plan, I'm gonna have a look on Saturday.
I'm not entirely sure what voltage I'll be looking for, I'm just going to look to make sure there is power going through, no matter the voltage.

I have a hunch that it will be more likely to be the compressor than the relay, so I don't see it being a cheap fix.

If it does turn out to be the compressor, I don't think I'll end up repairing it for another few months as I have a holiday to pay for first. Knowing my luck, when I do get around to finally sorting it, the hot weather will be long gone!

 

[Israar]

Same mate!

Have you managed to find time this weekend? I'm having trouble getting to the cable if I'm honest so going to leave it for now, when I have A/C ON and the recirc on too, the pulley and clutch looks to be spinning, though I'm still not 100% on what the problem is... I have no A/C errors on the ECU.

I want to test the relay but looks like there is only one relay in my fuse box under the bonnet, so going to get clarification first concerning it!

Aye, I can live without A/C for now but it will be a "to-do" on my list, my most important once I have the money saved will be Cambelt and Water Pump + Service (oil, oil filter and fuel filter), did Air and Cabin filter yesterday look like Cabin filter had never been changed though

--Lee

 

[iDan]

Hi Lee, sorry for the late reply!
I managed to get it up on the lift today and have a fiddle around!
I found that my lead going to the compressor is only pushing through ~3volts, which you would imagine it would need 12v.
Next I used a power probe to push 12v through the compressor to see what it would do.
With the engine running and the 12v being pushed through, I could hear the solenoid click, which would engage the clutch, but the temperature still didn't drop.
I don't know if 12v is enough to make the A/C turn on or weather there is other variables the car might need to see to get it to kick in.

I took it to a garage and he said we will try to rig up a permanent live 12v to it, so we know the clutch is engaged then he will plug it into his air conditioning regas unit and check that the pressures are right, to see if the compressor is working.
Not sure where we'll go from there, but that's the next step. Probably won't be able to do that this week, as the mechanic is a friend and he's doing it as a favour when he's quiet.

The saga continues

 

[Israar]

Hey Dan, don't be sorry for a late reply mate, you've got other things to do also, I just appreciate the fact you get back, in doing so hopefully we can sort the problems out so if others experience it can be less troublesome for them and not as costly too?

I've not yet tried mine, I'm speaking with another chap on here who's going through what we are haha! It's a pain but still something that would be nice for us to close the case on!

He mentioned on ignition on he got 3.5v and engine on 12v-13v if that is true then the pressure switch is regulating power properly and the pressure switch should be running a constant 12v with ignition on. The guy who stated this is benholden2015, he is the one who should take credit for me saying this as I would never have known this without him testing and stating it!

Do your fans kick in when you turn on A/C? I don't know whether or not mine do so need to check tonight or tomorrow (before / after) work haha! I'm trying out all the cost free trials to keep diagnosing as little as possible!

It's nice your friend is able to do that for you matey, hopefully you just need a full recharge to run or maybe a leak somewhere? Nothing too costly I hope!

This saga will end in due time! I have high hopes for us all!

--Lee