W211 interior heating issues.

[NickPlymouth]

Hi all.

I have recently bought a 2004 E320 CDi and there is no heat coming into the cabin. Its the basic dual zone system. After a search, it seemed the problem would be the duo valve/heater shut off valve so this has been replaced with no effect.

The outside air temperature reading was miles off, so the sensor was replaced and I now get sensible readings, but no effect on interior heat.

I have tried an alternative control unit (including a digital one, but this makes no difference.

The fan operates as you would expect - if the interior is cold, but the engine is warm, the fan runs quite quickly.

What I have just noticed is that the air is always to the face vents and feet regardless of what the vents are set too. Nothing goes to the windscreen no matter what the setting is. I'm not convinced the aircon is working either although the a/c light does what I would expect.

Can anybody suggest what the issue(s) is/are. I presume they could all be related.

Apart from finding somebody with STAR, is there a way I can do some diagnostics using the panel (I've tried holding REST for several seconds, AUTO+RECIRC, but they don't seem to do anything).

TIA.

Nick.

 

[Alps]

i think STAR would be a good place to start, it could be a stuck flap somewhere

 

[NickPlymouth]

Fixed: W211 interior heating issues.

One of the leads into the back of the climate unit had dropped down during some previous work and was not connected. It was not visible with the climate unit removed and I only found it once I had removed the top part of the dash.

I connecte it up and there was much whirring of flaps and things moving inside. It all seems to work OK now :bannana:.

 

[Dave Richardson]

Glad to hear that you've found the problem & been able to get the heating back working. One comment is look up the guys at Mercare the Plymouth Indie, who have recently moved their workshops to the Estover area

Dave