AC problem (and a long way from home)

[yatzee]

Hi Guys,

I'm on vacation with my 04 Wagon and my AC quit working.

The clutch isn't engaging. I've checked the low side pressure and it's 100 psi. What else can I check? I have limited tools (I'm in Nashville)

 

[KLXD]

With the key on and the AC on do the engine fans run on low?

There's a troubleshooting guide on here for AC.

 

[yatzee]

yes, they do. Didn't find the troubleshooting guide

 

[KLXD]

Top sticky on this, the A4 Forum. Actually refers to condenser fans but it'll help you.

 

[cfm56]

i had the exact thing occur to me on my recent road trip from socal to wa state. I haven't trouble shot it yet, but i know my drivers side fan is inop in the low speed setting, the compressor does not come online at all. Im betting on the compressor having retired. However, i suggest you do the troubleshooting tree on here and verify all your fuses are fine as well as your terminal connections related to your fan/ac system. Goodluck

 

[yatzee]

a quick update -

- both fans are working as they should
- no signal is going to the clutch
- checked the signal coming from ac pressure sensor G65 - nothing, but i'm not confident in my testing. But as it stands right now, I need a G65. It's only 97f here today....

 

[Brokk]

How do you know if the fans are spinning fast or slow? They seem like they are going fast to me but they could go faster...

 

[yatzee]

I've seen them much faster than today

 

[Enabled]

I assume you did the simple check of the fans with the key in ignition, engine off, and AC on. So if the fans turn on then, they are in low speed.

I believe that the pressure switch going bad would not turn on any component of the system, meaning that the fans wouldn't kick in as well. Someone please confirm. The pressure switch has a final say if the system will work altogether. At least this is how it is on other cars.

Clutch wiring is intact?

 

[yatzee]

yup, i've tested the fan and they are coming on. The wiring to the clutch appears to be ok - there is no signal going to the clutch. I am thinking that the pressure sensor is the issue, but being far from home, i'm not really in a position to lift the battery to check the T14

 

[Dave_D]

yup, i've tested the fan and they are coming on. The wiring to the clutch appears to be ok - there is no signal going to the clutch. I am thinking that the pressure sensor is the issue, but being far from home, i'm not really in a position to lift the battery to check the T14

You may want to check your wiring for continuity. On my 1999.5 the ground wire was broken free at a wiring block between the clutch and the FCM under the battery. My A/C was intermittent until I fixed this.

Dave