Charging A/C 06 Jetta

Does the system need to get to a certain low side pressure for the condenser fan to come on while charging the system? I have 60 psi on the low side and 0 psi on the high side. Btw, I just replaced the compressor control solenoid.

I did a lot of searching and the fans should come on at 150 psi high side pressure. The problem is it won't take the charge, I'm getting 118 psi on the low side and 125 psi on the high side. The A/C worked fine before I had it evacuated to fix the RCV, wanted to fix the delay. Btw my pressures were correct before. I have tested and tried the old and new RCV and they both function properly. Reading this here ( http://www.agcoauto.com/content/news/p2_articleid/257 ) would point to the compressor, but the oil is clean. Can the fans be tested without a vcds, ie: jumping the pressure sensor?

Not sure what you are asking here.

I let the machine do its thing... which is pull a vacuum for a while, the longer the better but I gauge that by the nature of the reason the system was open in the first place. For just a quick RCV replacement I let it run for 10 minutes. Then once done, I dial up the charge amount, 750 grams or whatever it is, the machine charges it, I unhook the lines, put the caps back on, shut the hood, start the engine and drive it out of the shop.

I make sure the air is working and I will usually then jump out when I get back to the shop with the engine still running, air still on, and pop the hood to make sure both the fans are running.

The fans do not come on until you drive it, does the RCV control the fans?

The fans should come on, low speed, when you turn the A/C on, engine running or not, car driving or not.

If your fans aren't coming on with the A/C you've probably got other things going on besides low charge.

The fans came on after I took it for a drive and I was able to charge it to spec. Was cooling to 45F sitting in driveway until the fans quit again. Going to go for a drive now and see what happens.

Works perfect now, Thank you.

Found the problem, it needs a compressor. http://www.sanden.com.sg/opencms/op.../Technical_Support/troubleshoot/hfc_134a.html page 2 high low pressure, low high pressure. If replacing RCV you cannot go to a shop and have the refrigerant recovered and then go home and put the valve in and drive back to get it charged. My pressure readings were perfect before I started the repair. Driving it will burn up the compressor. http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf Page 28. Hope this saves someone some money.

Vince Waldon said:

The fans should come on, low speed, when you turn the A/C on, engine running or not, car driving or not.
If your fans aren't coming on with the A/C you've probably got other things going on besides low charge.

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This is a false statement on the A5 cars. The fans only will come on once a preset amount of high side pressure is detected. So the engine MUST be running, and the compressor MUST be working.

usernamehere said:

Found the problem, it needs a compressor. http://www.sanden.com.sg/opencms/op.../Technical_Support/troubleshoot/hfc_134a.html page 2 high low pressure, low high pressure. If replacing RCV you cannot go to a shop and have the refrigerant recovered and then go home and put the valve in and drive back to get it charged. My pressure readings were perfect before I started the repair. Driving it will burn up the compressor. http://www.sanden.com/productlibrary/manuals/SD_Service_Guide_Rev_2.pdf Page 28. Hope this saves someone some money.

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This seems odd, as that would mean no charge, as from a leak, would also ruin the compressor, and that is not the case, as our body shop drives cars over here all the time to get charged up. I have never seen a compressor fail from this.

You might be able to drive a short distance. I went a few days and a couple hundred miles. I ordered the wrong part. The compressor was so hot it would burn you after a ten mile trip. Anyway, I have a really good re builder close by I'm going to use them. They can bench pressure test it off the car.

I've seen them driven for a couple YEARS, because of a leak that the owner could not fix (condenser, from a crash), and they finally had me replace the condenser, I charged the system, it is still working fine to this day.

So long as there is some oil in the compressor, it should be enough to keep the shaft lubricated. There is no load on the compressor when the A/C is off.

I certainly do not recommend this, but I have never known this to be an issue.

The A/C compressor housing WILL get hot... it is bolted to the side of the engine.

oilhammer said:

This is a false statement on the A5 cars. The fans only will come on once a preset amount of high side pressure is detected. So the engine MUST be running, and the compressor MUST be working.

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A5, ah yes, good catch Brian... I stand corrected.