Aircon Relay Location
- Thread starter Lynx
- Start date
Hello, I've a problem with the Aircon not working. The lights and blowers are working but not going cold. I've checked the fuses, changed the pressure sensor and had it Re-gassed and checked all connections. I was thinking if it was a relay problem before I get the compressor changed.
Yes I turned the centre wheel above the vents to blue, fans start straight away, but I can't hear any change when I turn the aircon on. I've done some research on how to test the compressor clutch with a multimeter, so I'll give that a try tomorrow, but it looks like it's going to be the compressor that's the problem.
At the summit of the picturesque fens
If the clutch on the compressor is not engaging (you should be able to see it spinning or not), check electrical connections on the connector to the clutch and at the clutch itself. I have seen many in the past with broken or damaged wires at the business end. However, if the revs don't rise when the a/c is switched on at tickover, it is most likely a control issue as you said.Lynx said:
How long ago did you have it charged (re-gassed) and was there any issues with leaks? If the system hasn't got enough refrigerant (gas) then the low pressure switch will hold the clutch off. Worth finding and checking whether the switch is open or closed. HTH
Hello, Checked all the wiring and all seems fine.
The compressor spins all the time, and there's no difference in the revs when I turn on the Aircon.
The clutch seems to be at the back of the compressor and not at the front. (See Photos)
Had the gas checked a couple of days ago and it was fine, so no leaks. Put in a new pressure sensor and still the same.
I've tested the clutch with a multimeter and it's showing 11.4 ohms, and it should be between 2 and 5 ohms, so it looks like it's the compressor.
I'll attach a couple of photos of the compressor I'll be buying online for you to see.
If anyone has the E89 2.3i could they have a look and see if the compressor spins all the time?
Thanks for you help.
The compressor spins all the time, and there's no difference in the revs when I turn on the Aircon.
The clutch seems to be at the back of the compressor and not at the front. (See Photos)
Had the gas checked a couple of days ago and it was fine, so no leaks. Put in a new pressure sensor and still the same.
I've tested the clutch with a multimeter and it's showing 11.4 ohms, and it should be between 2 and 5 ohms, so it looks like it's the compressor.
I'll attach a couple of photos of the compressor I'll be buying online for you to see.
If anyone has the E89 2.3i could they have a look and see if the compressor spins all the time?
Thanks for you help.
Attachments
Those pictures are a bare compressor with no clutch attached. Unless the solenoid is inside the casing (not seen that before).
I took a picture of mine (I couldn't show it spinning as the camera speed was too quick)!
The outer two parts from the pulley should spin when the a/c is engaged (on) and be stationary when off. Obviously the pulley spins with the crank; the clutch engages the pulley to the crank of the compressor which makes it turn and do all it's magic (!).
When you switch the a/c on the fan should start and the clutch 'pulls in' and spins. The revs should increase slightly to allow for the extra load of the compressor to prevent the car stalling at idle.
I took a picture of mine (I couldn't show it spinning as the camera speed was too quick)!
The outer two parts from the pulley should spin when the a/c is engaged (on) and be stationary when off. Obviously the pulley spins with the crank; the clutch engages the pulley to the crank of the compressor which makes it turn and do all it's magic (!).
When you switch the a/c on the fan should start and the clutch 'pulls in' and spins. The revs should increase slightly to allow for the extra load of the compressor to prevent the car stalling at idle.
Hello
Thank you for taking the photo, as I know there is not much room for your camera.
I understand everything you have said on the working of the compressor.
But mine is different (See Photos)
As yours is similar to what's on my E90.
I've done more research on different compressors and found this link on clutchless compressors which I think is on mine.
http://www.mechanexpert.com/compressors-without-magnetic-clutches/
I just wish they had put a magnetic clutch on mine, it would have made it easier to diagnose.
Thank you for your suggestions and I'll keep you updated on my problem. Cheers
Thank you for taking the photo, as I know there is not much room for your camera.
I understand everything you have said on the working of the compressor.
But mine is different (See Photos)
As yours is similar to what's on my E90.
I've done more research on different compressors and found this link on clutchless compressors which I think is on mine.
http://www.mechanexpert.com/compressors-without-magnetic-clutches/
I just wish they had put a magnetic clutch on mine, it would have made it easier to diagnose.
Thank you for your suggestions and I'll keep you updated on my problem. Cheers
Attachments
From those pictures it looks like the grey outer piece is still a clutch as it has 'cut-outs' and locating pieces into the pulley. Maybe it is just energised internally. Not sure TBH as not seen one like that before. It has been a long time since I worked on a/c on cars, though.
Keep us posted, as it is all useful information.
Keep us posted, as it is all useful information.
Hello
I take it that when the new compressor is delivered and fitted, that the clutch will engage while there is no gas in the system, as it will not be worth taking the car to get the system Flushed and Re-gassed if there is still a problem?
Also I will strip the old one down when it's off and see how this compressor works.
Cheers
I take it that when the new compressor is delivered and fitted, that the clutch will engage while there is no gas in the system, as it will not be worth taking the car to get the system Flushed and Re-gassed if there is still a problem?
Also I will strip the old one down when it's off and see how this compressor works.
Cheers
Lynx said:
No the clutch won't engage without sufficient pressure to make at least one safety switch (low pressure). The LP switch is a safety to protect the compressor from damage as it is lubricated by dissolved oil in the refrigerant. You can test it by sticking 12 volts directly onto it from somewhere. Just don't do it with the engine running. You will hear a click and should be able to see the clutch move. But that won't help determine whether the fault is elsewhere, it will just prove if the clutch works. Tricky one.
There is a thread where someone used an OBD reader (INPA??) which shows a display of all the electrical bits of the a/c system and the faults. Might be worth doing that before buying a new compressor TBH.