Ive read up on the issues with the monovlave, ive tested the plug - 12V at cold and 0 at hot, but that doesnt prove the monovalve is working.
Where does the car get the air in from? Should cool outside air come in when you have the EC button depressed i.e. cool air but no A/C on. Does the monovalve effect this knid of operation.
AND i checked with my local supplier and he quoted 320NZD to have a monovalve in form germany, WTF it cant be that expensive can it?
No, not the part itself to buy; I think I paid about 60 USD.
Yeah, if the monovalve is not working you could get cold air still coming in, the system ‘thinks’ there’s hot coolant running through the core. Do you have ACC or the desirable manual type? If ACC you can also get cool air as the system responds to the cabin air temp sensor, even with the compressor off.
The aux water pump gets the hot coolant to the valve which in turn sends it to the heater core. Usually the valve fails open not unlike the t stat in the cooling system but as you noted there could be an electrical problem. The valve may also have fouled closed, not allowing coolant to the core.
yep figured that one, will cost 115NZD for the repair kit not the whole setup. I took the valve out and had a good look, the main rubber diaphragm is intact as are all the others. I replaced the climate control unit with the one from my sec and still the centre vents dont seem to work, which is another problem, they just blow lightly and instead the defrost vents blow. Any suggestions?
i don't actually get any heat out of the center vents either, just the defrost vents...the only time I get air out of the center vents is if it is blowing out cool air, not heat. not sure about that one. I was just happy at the time to have heat , but would like to know if there is a fix....
I replaced the climate control unit with the one from my sec and still the centre vents dont seem to work, which is another problem, they just blow lightly and instead the defrost vents blow. Any suggestions?
If you changed the ACC push-button panel with a known good one and you still have problems with the vents - its either a vacuum leak in the vacuum distribution "tree" in the center console or the rubber diaphragms at the vents are shot.
The Monovalve regulates the temperature of the air, not which vents will open or close.
yeah ive read up on some W123 forums about the centre vents not working, im going to remove the vacuum actuator and gate, ill control the vents manually with the slider.
I realize it's been asked and answered a zillion times, but where exactly is the "monovalve" located in the engine compartment? Mine is suspect in my 560 coupe. Thanks a zillion.
I realize it's been asked and answered a zillion times, but where exactly is the "monovalve" located in the engine compartment? Mine is suspect in my 560 coupe. Thanks a zillion.
It is in the narrow space between the secondary firewall and the chassis. If you stand by the side of the car and look at the battery, the Monovalve will be about 15" further towards the oppsite side.
i don't actually get any heat out of the center vents either, just the defrost vents...the only time I get air out of the center vents is if it is blowing out cool air, not heat. not sure about that one. I was just happy at the time to have heat , but would like to know if there is a fix....
Since I'm not living in the US I couldn't order my monovalve with any of the normal autohausz etc vendors and I had avery hard time finding my monovalve.
However the original BOSCH number is :1 147 213 007 -711 supplied by Robert Bosch GmbH Auf der Breit 4 D-76227 Karlsruhe Germany.
Any Bosch shop should be able to order it for you.
Mine was apx 55 Euro's
seriously.....the center vents only blow the outside air, not heated air? I was unaware of this. Anyone want to chime in? Does your center vents blow heated air?
I tried to help my neighbor find out why his 2005 E 320 has no heat! Checked all fuses no problem. He has a button on the passenger dash side(REST?) when touching the button the light (which indicates function is on doesn't light up like on the drivers side! Just blows cold cold air no matter what temp is set on. Any help would be appreciated.
On the newer models light on means usually function off. Like the AC.
Rest means using the heat in the engine when the engine is of and you stepped out.
I have the AC Repair manual. If you need the position matrix, let me know. It tells what everything is supposed to be doing and when and in what mode all on one sheet.
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