I just replaced the compressor on 85 300D and loaded it with 134, all by procedure.
I'm not getting any Air Conditioning. I'm just getting heat, even though I can hear the Compressor "click" when I set the Climate Controls.
Can anyone tell me what I did wrong or what is going on?

85 300D-Post AC Compressor changeout. Why no A.C., just heat?

With a new compressor or another used one? Sounds like it is a bad compressor to me, I don't know much about them though. I believe that after the clutch kicks in should start pumping until it hits the preset shut off temperature where it shuts off before the freon could cause freezing in the lines. Yours doesn't sound like it is even starting to pump though.

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Jeff M.
Mercedes W123 DIY pages are now located here.
1983 / 1984 300D Sold
2000 CLK430 Cabriolet ~58k Sold
2005 Avalanche 4x4 ~66k

It's really hard to diagnose an A/C compressor problem without the proper pressure gauges. If you don't have them see if a friendly mechanic or A/C shop will do a quick pressure test to see if:

a. Compressor is pumping
b. Pressures on high and low sides are correct

Also, if you are replacing the compressor due to the prior compressor self distructing and didn't throughly flush the system you may have a blockage. If so flush the system pronto before the debris takes out the new compressor too. Oh yeah, you'll also need to replace the drier.

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LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

Make sure the monovalve isn't leaking, causing the heater core to run at full temp -- if the heater hoses are all hot, this is the problem.

If the valve is OK, it's the climate control pushbutton control unit, usually, although the coil can go bad in the monovalve, too.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter makes an excellent point. Before you do anything, run the A/C for a short while and then feel the A/C and heater hoses. It should help to give you a clue as to what is wrong. The A/C hoses around the expansion valve should be cool and the heater hoses downstream from the monovalve shouldn't be really hot.

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LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold