I have been through the A/C section of this forum a few times which has led me to test my A/C the way I have and led meto now understand a little about what it going on with my 1983 300D (w123 617 engine). But I am kind of stumped and if someone could point me in the right direction for the final solution, that would be great.

So I had the system charged with 2 pounds of R134 (I think i will switch to Freeze 12 but for now....) and it holds a vacuum. Pushing buttons on the climate control unit, I couldn't get any cold air to blow in the car. So I cut the wires to the compressor and grounded the brown wire, and jumped the Blue/green wire to battery and viola, the compressor engaged, the pipe in front of the valve cover (usually covered insulation but mine is lacking it currently) got cold and my mechanic said the high pressure was good but the suction was a little high (low side?) and said probably because the front fan was not on. However even after pushing every button on the air temp console, I still could not cold air into the cabin of the car. The buttons seem to appropriately direct air to the defrost, floor and front vents - although it appears that my two center vents do not operate. One other point, I did re-splice the compressor wires which I had cut and I am pretty sure I could here the compressor go on, but I do not think my front fan every went back on AND that A/C pipe that runs in front of the valve cover seemed to get hotter and hotter and of course there still was no cool air in the car.

Thanks
Doug

Check the foam tube running to the temp indicator, it's just below the glove box. Some have disintegrated, thereby giving the CCU a false reading.

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84 CD

Ok, I have some more data, so I hope someone could send me in the right direction so I do not have to pull the dash apart only to find out this is not the problem.

1. So, the heater controls seem to work. If I adjust the temperature dial, I can get the heat to increase or decrease. Pressing the various air blower directional buttons 'seems' to work except that the center vents do not blow.

2. The AC clutch engages and with nothing pressed on the climate controls, the the upper AC pipe gets cold, but no cold air in the cabin.

That is about all that I know right now. Does this give anybody a heads up to what to replace/repair next?

Thanks
Doug