Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hi, I do not see a reference to a previous question. Can you explain the problem that you are having and exactly what has been done so far?
I'd replace the complete mono valve assembly. It sounds like you are not getting flow through the valve. There is a check valve in the bottom of the valve that may be stuck closed.
Does the auxiliary water pump work?
Sorry for the wait I got pulled away from my computer.
Have you tried to bypass the aux pump with a fitting?
I know what you mean but I'd bypass it and see if it works with the mono valve connected.
You're going to need to get the blower going before we can go any further. I'd check and clean all of the fuses first. If the fuses aren't the problem you will need to check power and ground to the blower motor. The motor might have gone bad. In regards ***** ***** heat it sounds like you are losing the flow through the core or the core is partially plugged. All of your tests should be done with the defrost button pressed as that is a default for full heat to the windshield.
I thought you were losing the heat even with the valve bypassed. If it blows great heat with the valve bypassed I'd have to try another valve.
Replacing the valve would be my next step. You should be able to find used ones on ebay.