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MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
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Hi. The a/c in my 2002 Mercedes E500 is pumping hot air from

This answer was rated:

Hi. The a/c in my 2002 Mercedes E500 is pumping hot air from all vents, but especially from the rear vents. The inside of the storage unit in the console between the two front seats is incredibly hot. The control panel reads "off". New compressor was installed and refridgerant, but no improvement.

Any ideas?

MBpaul :

Hi, I would always recommend a check on a diagnostic tool such as Mercedes STAR to see if any fault codes are stored in the first instance but on this model the fault is almost certainly down to the heater shutoff valve failing - this also usually fails without storing any codes.

MBpaul :

When the valve fails it usually fails in an open position allowing hot water to constantly circulate around the heater core

MBpaul :

This results in hot air always coming though the heater even when set to cold temperatures

MBpaul :

If there are no fault codes stored then I would have the heater shutoff valve replaced as the next step

Customer: t
MBpaul :

This is located under the wiper mechanism which needs to be removed - it is tucked under the brake operating unit on the drivers side

Customer: Thanks.
MBpaul :

It is a bit tricky to access and remove when replacing for the first time!

Customer: Is it something Halfords should be able to fix or does it have to be MB.
MBpaul :

Any competent mechanic should be able to do the work - it does not specifically have to be MB althouth the part is probably a dealer supply part only

Customer: Thanks Paul.
Customer: I don't suppose that you have a diagram of the part / solution handy?
MBpaul :

I could probably find a parts diagram if that is any help for you - the actual workshop information I cannot put on here for copyright reasons Im afraid

Customer: The parts diagram would be very helpful.
MBpaul :

Click here: Parts Diagram - it is item #30

Customer: Thanks Paul. Much appreciated.
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