W202 Aircon Inop

[Tyro190]

Just taken delivery of a 1998 C2.5 Elegance Estate.

One known problem was the airconditioning didn't work. I'm now getting ready to have a look at the problem but just wanted to check to see if anyone had already suffered problems,and if so what the fixes were?

At the moment if you press the EC button the red light illuminates but nothing happens.

I have seen elsewhere that a lack of gas can cause the aircon to "shut down". Is this true?

What can I check to see if the compressor is "engaging", something I was told happens when the EC button is pressed?

There does not seem to be any adverse/strange noises emanating from the compressor.

Looking forward to any replies.

 

[BlackC55]

When the ec light if off the ac is on btw

 

[lynall]

Engine running look down the front at the belt and see if the centre of the air con pump pulley is turning.

Mine packed up the other week and the wire had broken to the pump.

If pulley not turning locate the air con test/charge points and remove the cap and have a quick poke with a screwdriver just as it you were letting a tyre down if you get a puff of oily air it probabky just needs a regass, if no puff of air you have a bigger leak and probably needs professional looking at it.



Lynall

 

[C230kompressor]

When the ec light if off the ac is on btw

lol i found that out after thinking it wasnt working!

 

[bennesspipers]

Thankyou all for this post,iv got one to check .

 

[Tyro190]

BlackC55 - Ifound that one out last night reading the manual, seems the wrong way round to my way of thinking.

Lynall - presumably the centre of the pulley should be turning with aircon ON (EC light off). What does it signify if it isn't? Are there any electrical connections to the pump I could check? You say:

Mine packed up the other week and the wire had broken to the pump

Did you fix it by mending the broken wire?

Where are the aircon charge points?

Sorry for the Qs but I haven't got a Haynes yet!!

 

[Will]

As said - EC light is 'Economy' mode, so you want that off for the A/C to be running.

If the pulley doesn't engage (there's an electronic clutch to operate it) then you have a fault.

As Lynall has mentioned, could be something silly such as a loose wire, but more than likely it'll be because of a loss of pressure in the system - usually through a leak, often the condensor becomes corroded/holed and the gas escapes - or similar.

There are two A/C charging points, one at the front near the condensor and another usually in the engine bay on the N/S.

Will

 

[Tyro190]

Thanks Will.

What do the charging points look like?

Do they have particular cap like on a tyre valve or something else to identify them?

Is there an electrical connection on the AC compressor? Hoping for a re-seat of the connector to end my woes.

Sorry for all the Qs but I'm new to AC, well I would be if it worked!

 

[Will]

Yes, they are similar looking to tyre valves with a screw on plastic cap IIRC.

Out of interest, do you have the digital LCD screen for the air con controls, or just the rotary dials to set the temperature?

Will

 

[stevesey]

Condensor leaks on 202s of that age are common - the condensor often rots where debris collects behind the centre of the electric fan hubs, or similar places (like in the corners).

 

[lynall]

My wire had broken just just on top of pump where there is a plug set up.

Pic is of of charging points on w210 prob similiar not hard to miss, bottom one hidden under pastic cover, when ac running the centre of the pulley should be turning.

Google aaron radiators got my condenser from them £80 ish iirc.




Lynall

 

[Tyro190]

Will - Rotary dials for the temperaure.

Is there a quick way to find out if the condenser is shot? I'd hate to pay for a re-gas only to find it leaking from the off.

Kwik-Fit do a re-gas service I think, would they test for leaks first I wonder?

Lynall -

My wire had broken just just on top of pump where there is a plug set up.

Was this the problem and did fixing it repair the AC system?

 

[stevesey]

Is there a quick way to find out if the condenser is shot? I'd hate to pay for a re-gas only to find it leaking from the off.

Kwik-Fit do a re-gas service I think, would they test for leaks first I wonder?

A leak test should be part of the procedure - although this is not always conclusive a) it may be a very slow leak and b) the test is normally done by pulling a vaccum, whearas the system is normally under pressure.

If you ask them to put UV dye in this should help in finding a leak later if it does leak out.

 

[lynall]

A leak test should be part of the procedure - although this is not always conclusive a) it may be a very slow leak and b) the test is normally done by pulling a vaccum, whearas the system is normally under pressure.

If you ask them to put UV dye in this should help in finding a leak later if it does leak out.

Thats exactly what i did at work even though the condenser was holed the system held a vacuum for long enough for the machine to be happy to allow the system to be refilled, then once filled i could see all the dye coming out all over the condenser.



Lynall