Forgive the noobie post. I've been reading threads for hours and I'm getting things confused in my head so I thought I'd just post up and ask.

i just picked up this car a week ago. '06 R53 with 95K on the clock.

My AC quit the other day. It was the hottest day we've had this summer and I was pushing the car pretty good. I've verified that the system is charged and the compressor is not engaging. Based on everything I'm reading...I'm guess that it's either the low speed fan resistor or the AC compressor clutch coil.

Does the compressor need to see the low speed fan kick on before it will engage??? or does the low speed fan need to see the compressor kick in before the fan turns on?

I've already ordered a replacement fan from RockAuto (I know it's going to fail eventually so I figure I'll get in front of it now), but I'm trying to understand the issue. I went out to the car this morning, it was 55 degrees out and I hit the AC button. Neither the compressor or the fan kicked in.

 

Could have saved some money and bought just the resistor. See the DetroitTuned site. Look for the 'dorman gen 1 fan relay kit.'

 

RockAuto also sells the resistor at half the price DT does.

 

As far as not having A/C goes.....

A/C comes on, then LSF about minute later.

A/C will work even though LSF does not with A/C off.

IMO if your compressor does not engage, you either have no R134A in the system or the A/C compressor is shot.

 

Thanks. I had the pressure checked on the low side confirming that there is r134 I the system. I just metered out my AC compressor clutch coil and it showed 30k ohms indicating that is the culprit. I'm going to order the coil off ebay and give it a shot.

 

^Good call. Hope you sort it out.
If your low is shot, hi comes on when A/C pressure reaches 18bar/261psi. Low is called when pressure hits 8bar/116psi.
If clutch won't engage, fan won't be called unless your coolant temp reaches 221F for low & 234F for high.

 

I've got an issue similar to WingZombie and I'm trying to decide if I should take the time to try replacing the clutch, or if I should just give up and have the mechanic replace the compressor. This is on an '04 with 140k miles.

The symptom that my wife reported was that the air was abnormally cold. She turned the A/C off for three minutes and then turned it back on and it would no longer blow cold air. She also said it had been producing a mildew odor.

I took it to have it diagnosed (already feeling ripped off about that but I'll spare you the details) and they said it was the compressor. They would also replace the receiver drier if they did the repair.

Knowing that they don't want to replace just the clutch, I checked the resistance as stated in this article and I got a very low reading meaning it appears pin 87 was well grounded.

With this information, do you think I should attempt to replace just the clutch? Or should I have a shop replace the whole compressor?

 

Thanks, this was exactly what I was looking for. Much appreciated.

 

Just an update. Per this thread over here, I replaced the AC clutch coil this morning and it solved my issue.