A/C Fault W205

[Deano240]

Hi all,

My AC has stopped working, I have checked the clutch by putting 12v on it and it works.

If i unplug the clutch and slightly plug it in the clutch engages and it runs OK (no cool air though) whe I fully plug the plug in it will run for a further 10 seconds then stop.

The AC light won't come on, sometimes it does but the clutch doesn't engage.

I know there's gas as I have checked this with gauges (I'm an AC engineer)

This is really throwing me off now any one else had this or know what could be wrong?

 

[MrGreedy]

If you hook up to diagnostics via OBD, what pressure is the aircon pressure sensor giving from cold, without running the car? Should be about 5bar when the car and engine is fully cool?

Are there any fault codes logged when looking using STAR?

 

[Deano240]

If you hook up to diagnostics via OBD, what pressure is the aircon pressure sensor giving from cold, without running the car? Should be about 5bar when the car and engine is fully cool?

Are there any fault codes logged when looking using STAR?

Would a icarsoft mb v3.0 tell me this? A garage wants £80 to connect to it and they didn't sound to confident. I'd rather spend the £180 and do it my self if it tells me

 

[MrGreedy]

yes, you can read pressure sensor live data with icarsoft (I have v2.0 I think) and get a good stab at most fault codes.

 

[Tonye]

Had mine done a few weeks back, just stopped. Went into my local indi, gas perged, vac test re gas and nowt, tested clutch fine, turned out to be the pressure switch at bottom of rad. £54 from merc, £280 the lot. Was up and down the lift all morning.

 

[Deano240]

Was your fan on all the time? Mine isn't on so wondering if it thinks its low pressure

 

[Tonye]

Don't think so. The cabin fan would only blow very hot. AC was working fine the day before so I thought it had lost all its gas but it hadn't.

 

[Petrol Pete]

Did OP mean the main fan on the radiator ? it is linked to the A/C

 

[Tonye]

Yes,
Answered with , don't think so, then went on to cabin fan.