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Discussion Starter #1
I have a very strange air/con problem with a 52 plate 1.8 Laguna. the system is ok up to 2500 rpm (always the same speed )when the compressor is heard (and felt) to cut out, from then on warm air is all I get, when slowing to 2000 rpm the compressor cuts in again and all is well. The system is not in need of gas and the pollen filter is new. Anyone any ideas as it is driving me round the bend.
 

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Hi Dave - there is a sensor at the evaporator which operates the clutch on the compressor - this is to regulate the flow of refrigerant. Both the sensor and clutch are sensitive to voltage changes so it may be prudent to check the alternator voltage output first (both at idle and at the speed when the compressor cuts out.):)
 

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Discussion Starter #4 (Edited)
dave the rave

Mmmm, no good ,the voltage is steady as a rock at 14v. I am tending towards thinking of a spurious command signal from the ECU to trip out the compressor clutch at 2500 rpm and back in again at 2000rpm, I know that the compressor is de-clutched under acceleration conditions, to provide more power for accelerating, but mine seems to be happening no matter how slowly you press the throttle and is rev. related.
 

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Hi dave - if the alternator clutch cuts out when engine is under acceleration and is controlled by the ECU - how does the ECU know when the engine is under load. I may be wrong but I believe MAP sensor in the inlet manifold detects changes in vacuum and airflow and sends information to the ECU. It is a possibility and it may be worth checking the MAP sensor.

P.S. Has the aircon been checked for refrigerant as I know if the level is low the clutch will not engage properly.
:)
 

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Hi, first time posting so any apologies for any mistakes etc..

i have a laguna privledge 03, climate control.

I too have a similar problem where aircon works fine upto approx 2000 revs. If i go above this just get normal air (warm). Once i drop the revs below 2000 again the cold air kicks in again. (This is proven every time, by me sitting in the car on my drive, and pressing the throttle so that the rev counter goes above 2000.)

Would love to know what the soloution to this problem is as its starting to bug me. (I had the compressor changed 7-8 months ago as it totally packed in)
 

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A/C cutting out above 2500rpm

I am experiencing the exact same problem outlined in the thread.
A/C cuts out when the engine is revved above 2500rpms.

A refill of refridgerant is recommended earlier in the thread.
Did this resolve this issue?

Thanks,
Ulf
 

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Discussion Starter #8
Hi- the Map sensor informs the ECU of engine load, so while standing still it should have minimul effect-how about something like the throttle position sensor which tells the ECU of the throttle opening, and would account for why the clutch cuts out regular as clockwork on a rev related basis- the 'gas' volume has been checked and is ok.

It really is a strange one!
 

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Hi Dave - the air-con compressor must have a relief mechanism to prevent it pumping too high a pressure otherwise something would give. I suspect it's electrically controlled as the compressor clutch will only operate when the refrigerant gases are OK. Looking through my Haynes manual for the Laguna II it refers to a air-con cut-off relay which is electricaly operated. Unfortunately the manual does'nt say where it is but I suspect in close to the blower motor. As it is electrically controlled have you checked the voltage output of the alternator at the revs you describe.:)
 

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Re: Same problem

Hi Everyone, just wondering if anyone has solved this strange problem yet, as i have the same trouble. As soon as i go over 2.500rpm the air con fails.:steam: I have tried phoning the main dealers but they are not much help, unless you want them to strip the system down for £££££££
 

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Thanks Noel for the link, can you just clarify, do you think this problem is down to the coolant mixture being wrong, or as in some other posts is it a problem with the aircon internal sensor? Quite a few people look as if they have the exact same problem, did fixing the coolant levels solve the problem? Just wondering if you have heard anything more on this. Any help much much apreciated.
 

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Hi Djen - I take it when you refer to coolant level you mean the amount of refrigerant gas in the air-con system rather than the water anti-freeze system for cooling the engine via the main radiator. If the air-con system has the wrong amount the compressor clutch will not engage correctly. What appears to happen is when the compressor starts to compress the gas its volume will decrease and the compressor then assumes there is insufficient gas available and deactivates the clutch - also remember the seals in the compressor require a special lubricant to work correctly. This is added when a proper air-con service is carried out. If the seal can't hold the gas it will dissipate and the level of gas decreases considerably.:)
 

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Discussion Starter #17
Afternoon all, I did get the gas checked, it was down a bit ( topped up) but the problem is still there- only that when the A/C does work it is cooler!!

Dave.

I feel a change of car coming on.
 

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Have the exactly same experience with my Laguna II.
I serviced the aircon and the technician told me that the a/c system was almost empty. I have had the system completely refilled and the machine used said that the whole system is healthy(it did a compressor check as well). However, the problem remains the same, above 2500rpm, no cold air.....

over and out,
Ulf
 

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aircon moneypit

Hi there, I'm another unfortunate soul with the same frustrating issue with my aircon...I have a Laguna 2 Estate 1.8 Dynamique on an 04 plate.

I bought the car a few months ago with the aircon not working. I had the system filled and the aircon worked well but cut out at approx 2200rpm rising, and cut back in at approx 2200rpm falling. To date, I've had the system refilled, £45 and still the same fault. I took it to the Renault dealers for an £80 diagnostic and was told the aircon compressor was very probably at fault with an internal component breakdown and it would be £660 to repair/changeout the compressor. I then sourced a second hand compressor for £60, I had this fitted and the system once again refilled by a radiator/aircon company for £150. I still have exactly the same fault....except its now really cold at less than 2200rpm.

At the moment I've lost all faith in the 'so called Renault vehicle technicians' and am fighting to get my £80 back. I've also decided to get out my test meter and investigate the issue myself but, I could do with some wiring diagrams, can anyone point me in the right direction?

Same as yourselves, if I get any further on with the issue I'll let you know.

Peter
 
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