Its Summer - Must Be An Aircon Problem

[TheMoog]

Hi Guys,

 

(I'm saving my aux heater problem for the winter...)

 

I originally posted this in the newbie/trainee section - but I guess i really should have put it here.

 

 

We've had the Galaxy now for 6 or so years and generally it's been pretty good. But the last couple of years have been painful. DMF replaced, then drive shaft, front suspensions bits, plus new air con pipes, wheel bearing and alternator pulley.

Wife and kids love it and so does the dog....

Now the air con has packed up :-). I'm loath to spend more cash on it at the moment until I have exhausted all the things I can try myself.

Few more details, it's got climate control, dual front and rear air con (vents in the roof) and one single radiator fan. (150PS Ghia Manual 56 Reg)

My notes and investigations so far:
1) Compressor is not spinning up when the air con is turned on
 

2) Compressor pulley spins freely by hand so don't think the compressor is seized. 
 

3) Tested the voltage on the plug to the compressor and that's 0v, whether the aircon is on or not 
 

4) Confirmed there is pressure in the system, checked by Kwick fit and also I ran vcds lite and it there were no diagnostic codes for low or high pressure so I assume the pressure sensor is ok.
 

5) No fault codes found on vcds lite at all, apart from the faulty glow plug on the aux heater which I know about
 

6) Turn the air con on (auto setting) and the radiator fan does not spin up. Reduced the cabin temp,setting to make sure there is demand and still no change.
 

7) The  external temp reading on the dash and climate control panel look to indicate the external temp sensor is working ok  (17c) today when testing. I am assuming this is the same sensore used by the air conditioning?
 

8) Checked all the fuses in the engine fuse box. All ok.
 

9) Checked all the fuses in passenger fuse box. All ok. I did not go below level 1. Is there anything under there I should have checked? As far as I can see everything else electrical in the car is working ok.
 

10) Pulled the plug on the radiator fan and both the large 12v supply and 0v ground were good. Both yellow wire and yellow/black wire were 0v with engine off. Start the engine and yellow wire still 0v but yellow/black went to 12v. Did not change state when I turned  air con on or off.
 

11) Refitted fan plug and checked for fault codes and correctly picked up cooling fan1 error which i cleared.
 

12) Started the engine and idled for ages to get the coolant temp up to about 75c and the fan spun a bit but not what I would call at full speed.

 

Right now I am kind of stuck without a proper circuit diagram. 

Any suggestions on what to try next? 

Thanks for reading all that.

Cheers,

Ed 

[seatkid]

Kwikfit is not always a reliable outfit to check a/c, told me mine didnt have/hold pressure, but was actually perfectly ok, after regassing elsewhere (I use F1 autocentres nowadays)

 

Even without any gas, turning a/c to auto should start the radiator fan at low speed.

 

Check the connector to the pressure switch? (No I dont know where it is on yours, maybe near the horns)

 

Possibly a relay or fuse on lower level.

 

Just a random thought, check the battery positive connection, it has a number of other small wires connected there and these sometimes break off.

 

If I can find my (2004) TIS CD I might investigate and post later, but need precise details of year/engine, does your car have one or two radiator fans? If two are they belt connected or independent electrical units?

[TheMoog]

Hi Seatkid,

 

It has a single radiator fan.

 

Won't be home till the weekend, so plan on drawing up a list of things ready to look at then and get the year/engine info.

 

I think the pressure switch is down in front of the offside  wheel arch.  I was working on the assumption that if the wiring was dodgy I'd get some sort of fault code on VDCS, but thats something added to the list to check.

 

Any ideas what relays/fuses  are on the lower level?  I need to get a copy of the TIS as the haines manual I am working from is not the best for this sort of stuff.

 

Thanks, Ed

[TheMoog]

Ok - back for round 2.  Busy with other things last few weekends so not had a chance to look at this again.

 

The build date is 06/07/2005. MkII Ghia 150PS TDI Manual.

 

Can someone PM me a wiring diagram and hopefully a relay diagram for the second level. The ones I have found online do not appear to match - (Checking wiring colours against the single radiator fan controller)

 

Many thanks

Edited July 4, 2015 by TheMoog

[TheMoog]

Bit more of an update:

Disconnected the external temp sensor behind LHS grill.    Climate control registered ---C  as expected. Plugged it back in and climate control and dash readouts now say 9'C despite it being 20'C... Will this re-calibrate over time?

 

Also got to the pressure switch - only has 3 wires to it unlike all the wiring diagrams I have found. Turn it on with the pressure switch disconnected - no flashing of the climate control panel and no error codes registered with VCDS. Not what I was expecting.  I thought it would at least have picked up a fault code so I am now no so confident it what I am reading using VCDS.

 

Pressure switch has Brown, Red/Yellow, Black wires to it.

 

Any ideas?

[marinabrid]

i read somewhere on a vw site that the pressure switch only register a low or high pressure fault code   not if its faulty itself.    could be correct,   for the wiring try the other excellent galaxy site   where there is a member got wiring for everything and a mass of help also available    http://www.forum.fordmpv.com/smf2/index.php

[TheMoog]

Thanks MarinaBrid I have started a thread over there as well.

 

Ambient temp has now gone back to normal after I disconnected the battery.

Cheers,

TheMoog aka Ed