AC light flashes 3 times, then goes off

[MancMike]

Hi, guys.

I'm away from home so don't have my manual with me.

All was good yesterday but today, I went to put ac on and the little red ligh on the button flashes 3 times, then goes off.

What does this mean?

Thanks.

 

[DSM10000]

There is a fault, possibly the gas pressure is low or the switch that monitors pressure is faulty? It needs a proper diagnosis on Star

 

[MancMike]

Wonderful. lol had the car a fortnight.

It's still under dealer warranty, but the diag will cost me.

I might see if I've still got an AC pressure gauge laying around and see if t is the pressure then. If it is, I'll DIY it.

Thanks.
Wouldn't it log an error code? As I have an ODBII reader?

 

[Howard]

How will the diagnostic cost you ?

If it's under warranty , give it back and say fix it , surely.

They can't bill you to find out what's wrong with it.

 

[MancMike]

The dealer I bought it from is 150 miles from home. The deal is, that I have to pay for diagnosing the fault, and they'll cover the cost of the work up to £1000. It's from an independent dealership, not Merc.

 

[DSM10000]

I do not see how you can be responsible for diagnostic work, if so just get a garage to lose the diagnostic cost in the repair!

If it is the pressure switch it may not log a fault, OBD is unlikely to be of help.

See here:http://www.mbclub.co.uk/forums/electronics/160152-air-con-light-flashes-3-times.html

 

[MancMike]

Yeah I thought that. Hopefully it won't come to that though.

Just read that halfrauds do free pressure checks, so I'll do that first, fingers crossed it's just low pressure. The car is 6 years old.

 

[MancMike]

Well I've been to halfords. The system is showing lots of pressure, way too much pressure, but that's because the AC system isn't kicking in, the compressor isn't kicking in as the system thinks/knows there's low pressure.

I think I'm going to have to go to a merc garage.

 

[MancMike]

http://www.mbclub.co.uk/forums/engine/177674-where-ac-pressure-sensor-w204-m272-c280-3l-v6.html