I would still dispense by weight. Do 80 percent of what the car calls for. I can't remember anymore. Was it 2.2 lbs of r12?

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Eugene

10 E63 AMG
93 300te 4matic
07 BMW X3
14 Ford F-150 Fx2

Why don't you just retrofit the complete r134A set up they used when Mercedes converted the 124 chassis from R12 to r134a in 1992 and 1993?

My 1993 300E (3.2) "E320" had r134a from the factory, and it had the coldest a/c of any car I've ever had.

I took it to Vegas and Palm Springs several times when it was 20 million degrees F, and it always blew ice cold.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

That is the long term goal, but with R12 instead...It would be even BETTER

Condenser swap is definitely the first and most important part. I feel like no amount of cleaning could make me feel comfortable that it is shedding heat quick enough. Plus, the updated one could be larger.

Next weekend I will install the new condenser.

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

My '72 280SE 4.5 had been converted to r134a by its second owner (I'm the 4th owner), and it blows ice cold in any temp.

The entire a/c system has been replaced: compressor, condenser, evaporator, lines, fittings, even the switch in the dash.

One clue to its effectiveness is the huge condenser that was put in.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Mounted on the new condenser!



Didn't the later models have two modes of fan operation? How did they achieve this exactly?

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2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k

PM Arthur Dalton. He'll know.

I do know the fans spin together, either on low speed or high speed.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

There is a double coil resistor mounted just rear of the left headlight assembly. I don't know the part number. Low speed is triggered by the pressure switch on the receiver/dryer, and high speed is triggered by a temp sensor on the head.

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Well I jumpered 30/87 relay K10 as suggested by Arthur Dalton and the low speed worked, I then jumpered the pressure switch with Key ON and it worked too.

I need to measure high side pressure, but last year when I did it, I was reaching 360psi high side and it still would not kick on, so I assume the pressure switch is toast. I have a new switch in my parts box anyway from a long time ago, so I'll swap it anyway.

__________________
2016 Monsoon Gray Audi Allroad - 21k
2008 Black Mercedes E350 4Matic Sport - 131k
2014 Jeep Wranger Unlimited Sahara - 62k
2003 Gray Mercedes ML350 - 122k