I think that the pump is not working, if you have warm air in the car when it is set to cold, the duo valve is not working, or the control unit is not working
The pump is 150 in the link
I seem to remember that on a couple of American cars (not sure about Mercs) the A/C cut off under full power situations (ie, drag racing from light to light).
Could that be the case here?
I made it Malcolm, values are the same 0.20 ohms something like thisWith an ohm meter, put one test lead in the center pin, and test the resistance of the two other pins, they should both be the same, you have the multi meter set to Ohms.
So 1 test lead in the center pin, and test across the other 2, one for each side
Now you are too hot?????
Remember 0 volts on the valve = hot and 11volts = Cold.
But this 11 volts is a pulsed voltage, if it was a 11volts DC the duo valve coils would get hot and would burn out
Yes they are OK