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Discussion Starter #1
Hello Everyone (or anyone who reads this!!!!),

I am the 'prowd' owner of a 2004 T5 1.9TDI LWB with a a very low milage of 541,000.
I haver facelifted the van inside and out, retrofited oem looking front and rear parking sensors, uprgaded and modified the dash to take an RNS315 DAB, and fitted a flat bottom steering wheel.

When i performed the facelift, I realised that all the front radiators (coolant, condensor & oil) were coming to within and inch of there life, so I replaced all of them while access was easy. I also replaced the compressor, as I had purchased the van with non working air con. A couple of weeks after the front end was replaced, the alternator packed up! Found someone local who recondition it for penuts compared to a new one, and all was working fine again. A few months later, an intermitent coolant leak appeared, and with the hot weather began to get worse. After cleaning the engine, i discover the leak was coming from a Y shaped plastic branch attached to the passenger side of the engine. Fortunately this was near the top of the engine, and was relatively easy to access.

Now, if I haven't yet bored you, and you are still reading this, then HELP!!!!!!

I have found numerous threads on 2.5 TDI air conditioning, but very few on 1.9 TDI air conditioning.

As mentioned above, the van was purchased without working air con, so I replaced the compressor with a second hand unit, that had been tested as fully working. Once fitted, I took the van to be regassed, but the compressor did not 'kick' in or out, as if the clutch was not engaging. After assuming that the second hand compressor was knackered, I purchased another second hand compressor, fitted it, took it for a regass, and still nothing!!!!

I put a volt meter on the compressor terminal, and it was only getting 6.9 volts, ehich I presumed was not enough for the electro magnet to engage the clutch on the compressor. In light of the miles on the van, I considered that there may be a fault in the wiring, so i connected the compressor directly to the battery, and the clutch instantly engaged, and I had cold air for about 60 seconds, until there was a BIG puff as the compressor let some pressure and oil out. Not nowing this had happened at first, I desonnect the compressor from the battery, and tried again, and the same thing happened.

I know you are probably thinking 'what and idiot' but i have been melting in my van, and was desperate to have cold air.

I am aware that there is a pressure sensor, and a magnetic clutch relay 454, and assumed that either of these, and or the wiring could have been at fault, which is why I connected the compressor directly to the battery to check that it was working.

I didn't want to change the pressure sensor, as i didn't know whether or no the system should be de-gassed ???

And I didn't want to spend over £100 on the 'fancy' relay 454, not nowing if the the one I had was faulty or not !!!

I am not an AC expert, and would appreciate any and all help regarding fault finding the electrical system, and any switches or sensors I may have missed.

NOTE: I have VCDS, but as the van is a 2004, I am unable to acces 08 HVAC. I did do an output test on the compressor through the engine, but the compressor did not kick in or out.

Thanks in advance, even if you have just read my dribble above and are unable to help.
 

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Discussion Starter #2
*** BUMP ***

I have since replaced the pressure switch, and the 454 relay.

I noticed that neither the radiator or condenser fans are coming on, swapped the air sensor on front bumper with a known working on and still nothing.

To my knowledge the fan issue may be related to the air con issue, as I believe certain criteria need to be met before the van will engage the ac clutch, even on manual air con ???

Knowing the cooling fans were more important than the air con, I decided to buy a new fan control module (7h0 919 506 d), however they were £150 from the stealers, and I happened to find a 'new' one on eBay. I order the control module and upon receiving it, realised that the seller was a fraudster, and had put their old circuit in the new housing!!!!!

CAN ANYONE HELP ME ........ PLEASE ?

Is there anyone local that has a T5 with AC, that would be happy to let me try their control module to see if it is that before throwing yet more unnecessary money at the van. I can come to you.
 

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Can't help with the fan module because mine is a 2.5 with a different part number. Might be worth checking all of the fuses with a meter or a test light (including the ones under the bonnet) especially since you may have shorted something. I:
 

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Discussion Starter #4
Hi,

What I know so far:

1.The fans work if I test them with vcds.

2. I have 12v to the module, but nothing coming out.

3. If I unplug the ambient sensor the ac fun runs at full pelt.

4. I have replaced the 454 module.

5. Both fans work if I connect 12v from the battery to them.

6. I have replaced the temp sensor at bottom of radiator.

7. All fuses checked.

Cheers
Ben
 

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Hi mate, have you had any Luck with your air con?
I'm having the same problem. New compressor, 454 relay, pressure sensor, temp sensor and only getting
7 volt at the compressor. Out of ideas now hope someone can help. Cheers
 

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Discussion Starter #7
Hi,

What I know so far:

1.The fans work if I test them with vcds.

2. I have 12v to the module, but nothing coming out.

3. If I unplug the ambient sensor the ac fun runs at full pelt.

4. I have replaced the 454 module.

5. Both fans work if I connect 12v from the battery to them.

6. I have replaced the temp sensor at bottom of radiator.

7. All fuses checked.

Cheers
Ben
*** UPDATE ***

8. I have replaced tbhe fan relay module with a known working on ..... STILL NO LUCK!!!!!!!!!!!!!
 

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My radiator fan was running when I was stuck on the motorway, was going to change the
Fan relay next, but if you've tried it I'll leave it for now. Going try and get to an auto sparks tomorrow see if they can sort it.
Going over to France and Spain next week so need it working, I'll let you know if I have any luck.
 

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Any luck with the air con Ben? Changed my heater dial modual today as it was past it's best, and I wasn't
Getting a live feed to the pressure switch, and the air con started ?.
Not saying that's your problem but there's a PCB at the back of the dial that could have gone bad, £120 from TPS.
Hope this helps
 
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