Air Conditioning pump/compressor

andymcculloch · Post by **andymcculloch** » Sun Aug 13, 2017 7:58 am

My ac pump has stopped working, took it into Halfords to get the gas topped up but mechanic said the pump isn't cutting in, is it a big job to replace? DIY?

Mekon · Post by **Mekon** » Sun Aug 13, 2017 8:07 am

Spray the electric clutch on the front of the pump with wd40 might free it off mine was the same when I got it did that then put a bit of gas in now working fine

Ducklakeview · Post by **Ducklakeview** » Sun Aug 13, 2017 9:35 am

Remove the plastic cover at the front of the engine bay, the one with the bmw logo on it. Underneath on the drivers side you'll see the main power connector for the fan. It has two heavy cables and one very thin green one in the middle. My money is on the green one having corroded into dust where it enters the connector. Simply cut back and solder a replacement piece in. I've done a few of these now and ir was a right PIG to diagnose! The green wire is the fan speed input to the ecu, no fan speed = no a.c. clutch engagement signal!

Simples!

Oh and I wouldn't let Halfrauds near my a.c. with their amateur top up kit!!

Mike

ronk · Post by **ronk** » Sun Aug 13, 2017 7:05 pm

Ducklakeview wrote: ↑Sun Aug 13, 2017 9:35 am

Oh and I wouldn't let Halfrauds near my a.c. with their amateur top up kit!!

Mike

I wouldn't let them oil my bike!

andymcculloch · Post by **andymcculloch** » Sun Aug 13, 2017 7:20 pm

Hi, thanks for the tips, I'll give these a try, is there a low AC gas pressure sensor that stops the compressor running as well?, not sure I've read this somewhere or not?

Ducklakeview · Post by **Ducklakeview** » Sun Aug 13, 2017 8:39 pm

andymcculloch wrote: ↑Sun Aug 13, 2017 7:20 pm Hi, thanks for the tips, I'll give these a try, is there a low AC gas pressure sensor that stops the compressor running as well?, not sure I've read this somewhere or not?

Yes, there is a pressure switch in the system. Does the main fan come on when you turn the AC on?

Mike

Mekon · Post by **Mekon** » Mon Aug 14, 2017 5:41 am

There will be a low and high pressure switch the low to stop the compressor running and causing damage if it is low on gas and a high to cycle the fan on and off at set pressures is there any gas in the system when you put gauges on it ?

ronk · Post by **ronk** » Mon Aug 14, 2017 9:35 am

An AirCon expert told me that the re-gassing of a system should never be required.

He said if it needs gas, then there's a leak.

Is there any truth in his statement?

Mekon · Post by **Mekon** » Mon Aug 14, 2017 10:46 am

ronk wrote: ↑Mon Aug 14, 2017 9:35 am An AirCon expert told me that the re-gassing of a system should never be required.

He said if it needs gas, then there's a leak.

Is there any truth in his statement?

That is true it is a sealed system so should not need gassing but the seals dry out if not used regularly but the main problems are holes in the condenser from stones causing small leaks you can get leak stopper to add to the system to stop small leaks and also dye so you can find leaks the gas does not go off like kwik fit used to tell people

ronk · Post by **ronk** » Mon Aug 14, 2017 9:42 pm

I seem to recall seeing a glass inspection eye in a car with a level mark in the aircon system ?

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