Air Conditioning Problem

[2006Megane]

Hi All, first time poster here, just wondering if we have any Air-con experts who may be able to assist me with identifying a problem.

I have a 2006 Renault Megane Dynamique, when I press the Air Con switch on the dashboard the light illuminates but the compressor does not kick in - I have tried in vain to find the problem but as yet have had no luck.

For your information, I have been to Kwik-fit to have the gas level checked....gas level is OK and the system has no leaks (Kwik-fit do not charge if re-gassing fails, this cost nothing luckily).

Today I have explored the matter further, with the aid of my father we have ascertained that the clutch that engages the compressor is working fine (we removed the "Engine Multiplex Module" and with the aid of a battery was able to manually send 12v to the compressor clutch and activate this), It is thus unlikely therefore to be a compressor fault. We also tested the voltage at the compressor using a multimeter to verify if the voltage altered if you turned on the air con switch in the car (note that there is a connecting block into the front of the compressor, 2 no wires, a ground (black) and orange (presume power feed) - now this is where a fault appears evident, there is only 1.3v passing through the orange wire in both the on and off air con switch positions. Note that we also tested continuity between the compressor and the Engine Multiplex Module, and this appears ok.

Thus, in summary:

1) The compressor and compressor clutch are presumed OK.
2) The compressor is only receiving 1.3v from the supply (orange) wire regardless of the air con switch position.
3) Continuity between the compressor and engine multiplex module appears ok.
4) Light illuminates on air con switch in cabin but compressor does not kick in.
5) Gas levels in system are OK, no leaks according to Kwik-fit.

Any ideas? at the moment I am totally stumped.

Thank-you in advance for any answers, much appreciated!!

[dougieCC]

Aircon pressure switch.

Alan

[2006Megane]

Thank-you for the reply - presumably I can change this without affecting the gas in the system.

Am I correct in saying the switch is located behind the bumper to the bottom of the cylinder at the LHS of the condenser?

[tomalamix]

Yep,

Like Alan said...the pressure sensor switch. Its in the front of the car connected to the Air Con radiator. Looking from the front of the car its on the left bottom side of the AC radiator. Try to clean the contacts first, use some contact spray if you have and then try to engage the AC again. From what ive read on the tech manuals available on this forum i didnt find any info about the pressure switch typical resistance so i dont know any other way to test unless you connect the car via OBD scanner, it will tell you help you to know if the PS is ok or not...

BR

[nickyanc]

I'm an aircond technician.If the Pressure switch has 2 wires you can join them and see if your A/C works.Assuming that your A/C is full of gas(as you mentioned)bridging these 2 wires will bypass the P.Swtch and make A/C working.If your Pressure switch has 3 wires DO NOT BRIDGE/JOIN any wires,it means that your computer can read the amount of gas in the system by reading resistance.With an electrical diagram layout I will be able to tell you for sure if is safe to bridge any wires at P.Switch.One other thing you can try.You said that by applying 12V to compressor it will engage,if you can do that while the engine is running touch the big/thicker in diameter pipe/hose that runs from compressor to the firewall and see if it's getting cold(easyer to test on the aluminium part of the hose),if it does than you do have a full charge of gas.Be aware not to do this test longer than a minute otherwise you risk to blow the hose which run from compressor to condenser(radiator in front of the water radiator)

[2006Megane]

Update......

Have now got the air-con working, car went for MOT yesterday so asked garage to run a diagnostic check on the air-con system while it was in - turns out there was a fault code logged on the ecu that had locked out the compressor from working, a simple reset and now all is fine. The technician stated that the code error was a reported gas leak - assuming this is still present he states it is likely the error code will occur again and the compressor will lock out as before. Explained that I had previously been to Kwik-fit and no leaks/pressure etc. was fine.....so hopefully problem now fully resolved (assuming Kwik-fit tested the system correctly).

Thank-you to all for the responses.

[markren2004]

good result, so would disconnecting the battery overnight have sorted this or are these fault codes stored until cleared by an clip/ELM reader ?

[xv_biker1]

Bump!!
Anyone know about the error code thingy?
same problem here, just had it re gassed and looks like the compressor isnt engaging.
Just checked online for the prices £270! for the the compressor ouch.

thanks guys

[BobinFrance]

Hi everybody. My problem seems to be related. When I switch on the aircon I get a terrible noise, a bit like a belt slipping on a pully like used to happen when a water pump jammed in the bad old 50s. I took it to the local Renault dealer here in France and he's just phoned me to say the problem is the compressor and it will cost 1550 euros to replace. Probably about the current worth of the car, being a 2006 model. I am looking at sourcing a compressor in the UK and having it sent to France for fitting by a local garage.

Being new at this, I would be grateful if someone could advise me if I am doing the right thing.

Thanks. Bob

[ajsaville]

xv_biker1 if you know there is pressure in the system you want to check for any error codes relating to the aircon pressure. If it's logged a low pressure error it will disable the clutch until someone clears the error code.

[xv_biker1]

thanks ajsaville

i had it regased at a local garage. he showed me the printouts from their machine and it looks like it drains the system then refills it. Said recovered .08 of refrigerant and putt in .78 so im guessing it was pretty low. but it passed the leak test. He thought it was the compressor but said the clutch didnt seem to be engaging which i agreed with cause with all my others when you press the AC button the engine revs drop slightly before picking up and they werent

i found the same as you re the error code on the computer that stops the clutch engaging to protect the compressor so i called at the renault garage in wakefield to find out how much it would be to clear it, they wanted £80 +VAT (nearly £100) so i walked out. For 10 mins to plug into a computer? bet i could do it in 30 and ive never used one. Rip off merchants. Last time i had a diag done at the same place it was more like 30 - 40.

Any other way of doing it or anyone know somewhere in south yorks that can?
thanks
dave

[xv_biker1]

bobinfrance,
have a look online think i saw some for 270 recons,
try on here
https://www.automotive-air-conditioning- ... ompressors

just googled megane 2 air con compressor

did this ages ago for a mini alternator had to send back the busted part as part of the deal but saved a fortune over bmw price.

[BobinFrance]

Thanks xv_biker1. I've looked at your site plus a few others and ordered one to be sent to a friend in the UK. Another friend will bring it out to France. AgIn, many thanks. B

[drewster1978]

Hello ive got a problem with air con on mk2 2006,the light comes on in car when you press ac button,but didnt come on so took front bumper off and found the wires had broke on the connector to the ac compressor so bought OLENOID EXTENSION WIRING HARNESS LOOM 2 PIN and connected wires and still nothing then thought i buy a test light to see if there is any power in the wires and nothing..Would the fuse in the engine bay blown even if the light is on in car...Hope someone can help.thanks

[grandadbobby]

Hi,
not an expert on this but there is a fuse F4 in engine fuses (not connected to button according to almost useful Haynes )
You also got the pressure switch could be the trouble, plus test the clutch from battery.
Bob.