Aircon is not working. Light is on but compressor not kicking in. I have replaced the evaporator sensor and pollen filter. The outside temp sensor reads ok and the passenger temp sensor fan runs and I have had it and cleaned it just in case.
I had the aircon gas recharge at Kwikfit fit. It detected no leaks and says the system takes 650g and it only had 75g in it so was nearly empty (there may be decimal point in there somewhere) still the aircon didn't work. They put a diagnostic on it and it stated "compressor coupling open circuit" and they thought this was a break or electrical problem at the pump connector or circuit. They cleared all codes. To be fair to them they tried everything but couldnt get to the compressor wiring connector even on a ramp. Fuses are ok in the car but do not know which fuse or relay it is in the engine bay but as everything else works and the fans don't think it's the fuses.
What else can I check, it is very frustrating. Do I take it to a specialists aircon or diagnosis company or to the dreaded Renault?
My econd problem is the same as other posts, temp on cool up to 25 and hot only at 26. Changed the evaporator sensor, still no joy.
Help please! Fenando, I hope you are still posting.....
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The fault with "compressor coupling open circuit" may be an indication of the problem.Access to the pump connector is the way forward to establish if the power and earth supplies are present.There could be an open circuit coil winding to the compressor clutch.Sounds like an impossible-to-get to pump.hth
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I believe that our Elec & A/C Dr is on the right track. The compressor and wiring plug can be accessed from underneath. There is also a tri-function pressure switch to protect the refrigerant circuit, located at the bottom LHS of the condenser. I have nothing more helpful to add.
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Thanks for the advice. We had it on the ramp at Kwikfit and it was really difficult to see where it plugged in but looked like it was at the top behind some pipes and really difficult to get to. If I can get to it, how can I test it?
I am unsure how to test the pressure sensor although have removed and checked for damage before refitting. There seems to be some conflicting advice re checking this.
Re the open circuit, could this be due to the ecu switching the system off due to low gas? Would then leave an open circuit? I've read that some people have had to get Renault to reset the ecu.
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It is not easy to check the pressure switch manually.It is an electronic device that sends a signal to the engine control unit .This in turn will signal the compressor circuit.Easiest way to check the system pressure ,is via live data through diagnostic system.By open circuit,it means the magnetic coil that pulls the clutch in has a break in the windings and therefore cannot draw current.This condition is not affected by low gas pressure.The pump clutch coil is basically a solenoid.Low gas pressure can cause a fault to be logged in the engine control system ,and may need diagnostic equipment to clear the fault memory.If this car is fitted with the v6 Isuzu diesel engine,then the pump is most likely to be a GM/Delphi unit as fitted to the Vauxhall Vectra C.hth
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Thanks again. So we seem to be pointing towards the insides of the pump then so looking like a replacement. Looks like the diagnostics route is the way to go then. Will that have to be specifically a renault dealer?
I presume the aircon compressor would not have anything to do with the climate not blowing out warm until 26?
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You may be able to find a suitable Renault Service Centre rather than a full dealer outlet, as some RSCs offer reduced labour rates for older vehicles. If not, you need a technician with the software to interrogate the Renault CLIP (computer) system. The problem you mention is invariably resolved by replacing the evaporator sensor as per my earlier posts. Has the vehicle (with 2.2DCi engine?) done a very high mileage - ie is it likely that the compressor is worn out? And what year is it?
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Thanks Fernando, It is a 3.0dci, 2003 with 123k miles. I was so hoping the evap sensor replacement resolved the problem (at least the heat only at 26), unless of course the fault is in the wiring for the evap sensor!! What a pain it is to get to!!
Pump looks in good condition generally and the centre spins freely by hand with no noise. If I could get to it I could test t by putting 12v to it to see if the clutch engages, then I would know if the pump was ok. (or is that a bad idea?) I have seen so many people post that they have replaced the aircon pump at great expense to find out it has not resolved their problems.
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It is possible to test the pump with a direct power and earth supply,but there are a couple of points to beware.The connecting pins on the pump can be very small and easily dislodged to make reconnection of the 2 -pin multiplug difficult.Also the wiring to the pump is polarity conscious,so it is important to connect your direct feed the correct way round,otherwise you will blow the surge protection diode built into the clutch magnetic coil.hth
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It's probably best if I avoid that then! I am reluctant to change the aircon compressor until I have ruled everything else out. Judging by everything you have said a proper diagnostic sounds like the way forwards. Are we definitely saying that the open circuit is within the compressor and it can't be anything else?
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The fault could be anywhere,but a conclusive test is to see if there is power and earth supply to the compressor.If there is,and the compressor does not engage,then the fault lies at the compressor.This needs to be the next plan of action.hth
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Thankyou very much for all the advice. I will get this looked at and update with progress.
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I have seen the following aircon pump on ebay
VAUXHALL VECTRA SIGNUM 1.9 CDTI AIR CON PUMP COMPRESSOR GM 13197197 z19dth
You mention that the compressor is the same as the Vectra C but they all seem to be different. What is a Vectra C? Could this one fit? I have tried researching it but no joy. Thanks.
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Today I finally got to the compressor plug. On checking I noticed a split in the red wire which was permanently live and some of the core cable had split. This may have been because the ignition had not been off long.
I also noticed there was a split in the green wire which had been soldered (badly) and abother break in the cable further up.
I repaired all cables but compressor still not enagaing.
What can I do next? I am happy that I had 12v through the red wire but not sure about the green. When aircon is on should I get continuouty/12v if I put a tester on the red and green inside the plug? I am still hopeful the compressor is not shot. STill getting heat only at 26 though................many thanks
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The green wire is usually earth on Renault wiring.You need to put a test light(with a bulb of at least 5 watt) across the red and green wires to check for a good supply.You will need to have a/c on with engine running.If this test proves good,then I would think the fault is the compressor magnetic coil at fault.This part is external and can be replaced as a seperate part.hth
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Brilliant, thanks for the advice. I have a multimeter aswell so I presume that will work and should be 12v. As soon as it stops raining I will get under the car and do the test. Could this broken wire have caused the compressor coupling open circuit fault?
I have fried my brain looking at compressors. The 3.0dci seems to be a specific one from other vel satis and presume it;s not the same as the vectra/signum one and funnily enough the most expensive compressor. To ask a dumb question, where externally is the compressor magnetic coil should it need replacing? I thought they were inside. How would I go about getting this part?
If for some reason I do not have a supply then i assume it could be many things. I have changed the evap sensor, internal temp/humidity sensor seems ok, fan runs quietly and I have cleaned it just in case. OS temp reading spot on. All flaps seem ok other than the annoying heat at only the highest setting. Must double check I fitted the evap sensor correctly.
In fact I think I will answer that question myself.....diagnostic!
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A broken wire will not cause a compresor coil to fail.The pump will need to be removed from the engine to replace the coil.A special tool/puller is needed to remove the pulley/hub to acces the coil.The reason I thought (maybe?)that the pump would be possibly similar to a Vectra c V6d model ,is the 3.0 diesel engine is the same in the Vel satis.(made by Isuzu)hth
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No I didn't think the broken wire would cause the coil to fail I thought that maybe the "compressor coupling open circuit" fault could mean that there was an open circuit on the wiring to the compressor.
Makes total sense on the vectra V6, will do some more research if fault is at compressor.
I will do those tests on the plug tomorrow and go from there. I hope it's ok posting updates as it may be useful to someone else in the future. Thanks again.
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Right, tested the cables. 12v at the compressor red cable but no circuit when red and green tested together. Tried it with a multimeter. If I earthed the black negative of the multimeter on the body somewehere with the red on the red wire of the compressor cabling I get 12v. If I then moved the black negative to the green wire of the compressor wire I got diddly squat which tells me I have an open circuit, is this correct?
This was tested at the compressor connector from the car wiring harness which I had unplugged from the compressor. I also tested it with a light screwdrive I have with a jubilee clip and a wire coming out of the top. Again i got the same result. The weather was hot, the climate was set at it's lowest (16) and the AC button was illuminated. If I am understanding this correctly the earth supply is not complete, therefore the compressor cluthch could not engage. Could one of the various switches/sensors etc provide power by actually switching the earth rather than the live or am i being an idiot?
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Interesting progress.Looks like you may have an open circuit earth.I would tap another wire into the green wire and run it to an earth point.I very much doubt if the system uses a switched earth,but on some cars the earth circuit is taken through an engine coolant overheat switch ,so that the a/c is inhibited if water temp gets too high.Worth a try.May be an idea to run the earth through a 15amp fuse,just in case.hth
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Ah, not thought of that, makes sense. Tomorrow's job!
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tapped a wire into the green wire to an earth point but still no joy. I then ran it to the negative on the battery and the compressor clutch kicked straight in. Does this mean the pump is okStill no cold air though. I also noticed that the outside temp was 30C and yet when I had the climate at the lowest setting on 16 and hit the auto button the fans slowed right down as if the car thought the inside temp was 16. Unless it realised that the air coming through the blowers was too hot?
Any new suggestions?
I just have the feeling that something is not switching.........................
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I am starting to get a little confused.If the system has the correct amount of gas fill,and the compressor now cuts in,then the system should work.Let the compressor run for a few minutes(to stabilise) and check the temperature of the 2 pipes attached to the pump.One pipe should be hot and the other cold,this should be the case whatever setting is selected on the climate panel(obviosly a/c on)hth
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Me too! I ran it with the temp cable attached for about 15mins. Both pipes were still hot, no sign of cooling whatsoever. I noticed that i could not turn the compressor off with this temp wire attached.
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Have you considered this as per my above post? There is also a tri-function pressure switch to protect the refrigerant circuit, located at the bottom LHS of the condenser.
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Looking at the evidence so far,I would say that there could be more than 1 fault.I think my next plan would be to check if the correct amount of gas has been filled.No gas means inadequate pressure and the pump circuit will shut down.Not been able to find a wiring diagram for this model or any other Vel satis variant,probably because of their scarcity.The fact that the pump does nothing when electrically overidden tends to suggest that either the pump is faulty and or there is a pressure/quantity gas issue.hth
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Car been with a technician for last hour. Checked refrigerant first and all correct, no leaks. Said the only code is open circuit. He believes this "could" be a break somewhere in the earth cable. He said there are no faults showing on any of the sensors and getting the correct pressure adding from the tri pressure switch (I think that's what he said!) what through was that I said I bypassed the earth and ran it for 15minutes and still not cold. He's now off to check something else........
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I am even more confused now! he checked the refrigererant and said it was empty and I must have a leak. Topped it up, same fault code, cleared it, still no aircon. He said there was dye in the refrigerent but he could detect no leaks with an ultraviolet light and although the machine pressure tests the system he said they are not very good at detecting leaks unless they are massive! He said that the diagnostic system was showing a signal going to the compressor from the ECU (Presumably this is the climate control computer) and still thinks therefore that there is a break in the circuit. I have tried to trace the green cable but it was impossible. I checked the pins at the back of the climate control unit for the pressure sensor and this was showing 5v which I believe is the correct voltage for the pressure sensor. I also did a continuouity test from the compressor control pin direct to the green earth cable at the compressor and got continuoity which really threw me!
When i got home I ran a new cable from the green earth wire at the compressor, via a switch, to the negative on the battery. With the engine running I can switch the compressor clutch on and off and I finally get nice cold air. Not the best workaround but a temporary remedy. With the aircon then working does this mean the pressure switch has to be ok or could I have bypassed it with my workaround? Is there any way to check the pressure switch once and for all. If you have already answered this and I missed it i apologise!
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