DieselD
Member Since: 24 May 2019
Location: Wells
Posts: 82
 
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Hi all,
I have done various searches on this site for the problem I have but so far no joy, hopefully someone can help.
The issue is my Air con was not cooling and so I had it tested for leaks and re-gassed, all good for a while then stopped working again !!.
Today I had the system checked over again and think I have found the problem, on start up the viscous fan runs and the AC works fine but after a couple minutes the fan slows and the AC stops cooling.
The engine temp seams fine and not overheating, no fault codes ether.
I would imagine the fan should be told to run while the AC is on at low road speeds, does anyone know how the fan is controlled and what to look for.
Kind regards Dave.
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 29th Jul 2020 7:39 pm |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10360
 
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Fan is controlled by the engine ecu. and yes should run a little faster with AC on
The fan should always be moving a bit with the engine running.
If your theory was correct the AC would work ok while you were driving along at 35mph+ ish
and go warm a few mins after coming to a stop. So its worth trying that.
Read the engine fault codes if you can. I had a P0494-00 Fan speed low recently.
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| 29th Jul 2020 7:46 pm |
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DieselD
Member Since: 24 May 2019
Location: Wells
Posts: 82
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This is what appears to be what is happening Pete. We looked again today and NO fault codes !!, the fan just slows after a couple of minutes while parked, the system pressure rises and the condenser gets very hot so it stops cooling.
The fan is always turning but not fully engaged after a couple of minutes.
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| 29th Jul 2020 7:51 pm |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10360
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Well I guess you better try replacing the fan.
The only other thing to try is. With the engine running and warm pour boiling water over the coolant sensor at the front.
Be monitoring the coolant temp at the time to see it
Rise.
If it reads near 100 and the fans not running it proves another method isn’t increasing the fan spd
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| 29th Jul 2020 8:20 pm |
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