aircon schizophrenia E320

The EC button is EConomy mode. I have an intermittent problem.
When I press the EC button sometimes the red light comes on bright and the aircon is shut down and when I press it again the light goes off and
the aircon comes back on. This is as it should be.
Sometimes, however, the light only comes on dim and the aircon shuts down but I cannot get it to come back on by pressing the button again. It seems to be stuck in some intermediate state. Leaving the car for a day or so seems to restore it to a working state.
Obviously the compressor must be working since the aircon gushes cold air when everything is working but there must be a valve that sticks or a contact that is corroded. What are the other components to the aircon system on a year 2000 E320 cdi?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
That means there is something wrong with your AC system... with the EC light on all the time.
There is two great resources for this troubleshooting... look at earlier posts and you will find it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.