2007 Mercedes S550




Wishing all a healthy and prosperous New Year.








Last edited by clb0099; Jan 14, 2024 at 12:52 PM.
but I still think the main heater valve (black plastic bit beside the brake fluid reservoir) is electrically turned off - ONLY - because you don't have the comand system plugged in the car.....




my command is connected and still not heat. I was able to take out the (rest) auxiliary pump out but I am having a hell of a time getting the new one in. Anyone have instructions on install?
QUOTE=BOTUS;8907652]the rest pumps pump coolant - I guess - mainly through the heater matrix.... so I suspect it may well get you heat (when working)
but I still think the main heater valve (black plastic bit beside the brake fluid reservoir) is electrically turned off - ONLY - because you don't have the comand system plugged in the car.....[/QUOTE]
why not bypass the heater valve (in the short term) - as something isn't telling it to open from the sounds of it?
(with the car bolted up and connected as std) did you try with diagnostics resetting the madness of the HVAC system ? - multiple bits of user customisable madness available at dealer level fiddling - if they build in magic to turn OFF the AC unless you use dealer tools to reinstate - why wouldn't there be equal charge the customer madness for the heating....
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Last edited by BOTUS; Jan 15, 2024 at 08:31 AM.




that pump is a huge pain in the was to get out. There is a rubber mounting ring around it. I was able to get it out but putting in the new one is an even bigger pain in the ***. I have to try and figure it out today in 24 degree weather.
why not bypass the heater valve (in the short term) - as something isn't telling it to open from the sounds of it?
(with the car bolted up and connected as std) did you try with diagnostics resetting the madness of the HVAC system ? - multiple bits of user customisable madness available at dealer level fiddling - if they build in magic to turn OFF the AC unless you use dealer tools to reinstate - why wouldn't there be equal charge the customer madness for the heating....
.
The Best of Mercedes & AMG
I'm looking at the heater valve ('170) - on a poor parts schematic - top port seems to be the rest pump (#10)... I wonder if the ARROWS I added, suggests something like the way the coolant MIGHT travel around the heater system with the heater matrix on the ends of pipes 180 and 190 ????
I guess if correct or there about - the pump is not a positive displacement pump and it allows the flow all the time...
Last edited by BOTUS; Jan 15, 2024 at 11:30 AM.




sorry I don't have any instructions on the REST pump... not even sure where it is... its had to fathom why its difficult - is it a big circular mounting bracket... some heat / silicon lubricant ?
loads of pictures of it on this item
https://www.ebay.com/itm/264675569087?
swapped arrows
Last edited by BOTUS; Jan 15, 2024 at 11:31 AM.




why not bypass the heater valve (in the short term) - as something isn't telling it to open from the sounds of it?
(with the car bolted up and connected as std) did you try with diagnostics resetting the madness of the HVAC system ? - multiple bits of user customisable madness available at dealer level fiddling - if they build in magic to turn OFF the AC unless you use dealer tools to reinstate - why wouldn't there be equal charge the customer madness for the heating....
.
This is quite nice feature, actually.
...FYI in post#53 the other valve you mention inside the front wing ( I don't believe you have it) - on parts drawings they show two drawings (both very similar) but this valve is not on the std cars - only on cars with option rear heater controls








I am having my mechanic install the pump cause the ac lines need to be removed in order to replace it.




I just noticed that list article you added is for w211? I have w221?
,Figure 8 appears to have both hose nipples there in grey . i would start there.




