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Old 18th May 2022, 17:03   #1
suzublu
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Exclamation Aircon again

So, a few months back, got the aircon tested and found a leak, rotten condensor. This was replaced, retested and re-gassed all good Today went for a drive as it was nice, aircon on, hot air Got home and checked fan speeds etc, fine, but when I did the trinary test for the compressor clutch, nothing no kicking in whereas before it did. Does this mean compressor's goosed?
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Old 19th May 2022, 07:19   #2
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... when I did the trinary test for the compressor clutch, nothing ...
Can you confirm exactly what you did for this please Ron?

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Old 19th May 2022, 07:55   #3
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Sound like it is out of gas again or possibly the compressor relay in the underbonnet fuse box has failed swap over the 2 small relays and check again

Dave
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Old 19th May 2022, 08:11   #4
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Can you confirm exactly what you did for this please Ron?

Simon
Followed Jules' instructions Simon https://www.the75andztclub.co.uk/for...ht=testing+fan
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Sound like it is out of gas again or possibly the compressor relay in the underbonnet fuse box has failed swap over the 2 small relays and check again

Dave
Cheers Dave, I'll give that a go Can you point out the 2 relays please?
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Old 19th May 2022, 08:20   #5
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The relays are the 2 small black ones one is for the air con compressor the other is front fog lights just swap and try

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Old 19th May 2022, 10:03   #6
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OK, swapped the fuses over, no difference, tried the trinary again, clutch not engaging. The car has been making a whining sound lately, rises and lowers with revs, this all points to compressor to me I mean, it is over 20 years old now Think I'll make do without aircon for now
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Old 19th May 2022, 10:23   #7
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Thanks Ron.
As Jules' guide doesn't give the wiring colours for your petrol engine, there is a possibility that you may have inadvertently chosen the wrong one.

You need black (pin 4) and grey/yellow (pin 1) noting that there's also a yellow/grey (pin 3) which will have no effect upon the compressor clutch.

For what it's worth I don't endorse this test because it forces the compressor to run when there may be little or no refrigerant gas in the system, and since the lubricating oil is circulated with the gas this poses a risk of damaging the compressor.

I'd be interested to see if substituting another relay works. Relays are extremely reliable so I doubt it. I think your system has most likely lost its refrigerant. Was your air conditioning out of service for a lengthy period before you had it recharged a few months ago?

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Old 19th May 2022, 10:28   #8
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The car has been making a whining sound lately, rises and lowers with revs, this all points to compressor to me.
Does the whining stop when you select 'Econ' mode Ron? If not, it's more likely to be from the alternator or power steering pump.
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Think I'll make do without aircon for now
Don't bale out! Get it fixed, you know it makes sense!

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Old 19th May 2022, 10:34   #9
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You say you swapped the fuses? you should have swapped the relays if you swapped them and still not working then either bridge the relay or run a 12v supply directly to the compressor wire and see what happens

I have known quite a few of these relays fail causing this problem to check you have a good relay do the front foglights work if so the relay is ok then swap with the A/C relay

running a wire to test will not harm it for couple of mins as lets be honest you have nothing to lose as it does not work at the moment

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Old 19th May 2022, 10:54   #10
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You say you swapped the fuses? you should have swapped the relays if you swapped them and still not working then either bridge the relay or run a 12v supply directly to the compressor wire and see what happens

I have known quite a few of these relays fail causing this problem to check you have a good relay do the front foglights work if so the relay is ok then swap with the A/C relay

running a wire to test will not harm it for couple of mins as lets be honest you have nothing to lose as it does not work at the moment

Dave
Meant the relays Dave, the foglights still worked, but still no compressor
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