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1990 300sl =1976 450sl = 1998 e320 = 1999 c230 k =1999 corvette conv = 1996 corvette coupe
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Discussion Starter #1
can anyone tell me how to jump start my compresser -i am trying to see if i can get some freon in it to see if it works . thanks
 

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Greek God of the R129
SL500-500SEL-190E
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Yes if you give more info, like what is in it, etc.
Regards.
aam.
 

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1990 300sl =1976 450sl = 1998 e320 = 1999 c230 k =1999 corvette conv = 1996 corvette coupe
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19 Posts
Discussion Starter #3
a/c

when i turn the a/c on the compresser does not cut on , i am trying to put some freon in but becauce of the not coming on i can not add freon to see if the a/c works= i tryed jumping it at the saftey switch but nothing . thanks for any help.. sammy in tennessee
 

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2005 SLK350, 91 300SL with Pano Top, 04 S500, 2015 Tesla Model S
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When enough Freon is added at the low pressure valve, the pressure sensor will allow the compressor to turn on by itself. It will cycle quite often until more Freon is added and then the cycles should lengthen.
To get some initial charge into the system make sure that the ENGINE is OFF. Turn the can upside down to drain it in a liquid state. Do not ever do this with engine running or the introduction of liquid into the low pressure side could blow your compressor.
Once the compressor starts to cycle, put the can into a hot water bath to keep it from freezing up as more gas is drawn into the system.
Gauges should read about 65 pounds in the resting state and 30 lbs. or below at the low pressure side and about 185 lbs. at the high pressure side when running.
 

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1990 300sl =1976 450sl = 1998 e320 = 1999 c230 k =1999 corvette conv = 1996 corvette coupe
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Discussion Starter #5
thanks for the help - i will post how it works
 

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Greek God of the R129
SL500-500SEL-190E
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8,371 Posts
The info you got is good.
But I think that you have in R12 and you are adding R134
And that my friend is a big mistake.
You can not mix them together.
Regards.
aam.
 

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1990 300sl =1976 450sl = 1998 e320 = 1999 c230 k =1999 corvette conv = 1996 corvette coupe
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19 Posts
Discussion Starter #7
a/c

you are right my friend , it does have r12 but i know better than to add r134, but thanks for the advice....
 

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MB SL600, MB 380SE, Suzuki Grand Vitara, 38' Chris-Craft, Volvo V70XC, and my own two feet...
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R134 sux :rolleyes:

I still am in shock over R12 being phased out by the government.

If you really think about it, and add up the teacup-full of refrigerant that goes into an automotive a/c system, and then you figured every single car on the planet lost the full charge every year, it still wouldn't come close to the greenhouse gas emissions of just one or two coal-fired power plants. And meanwhile, here's the really stupid thing, R134a is just as toxic and flammable as R12.

The real story IIRC is a war between lobbyists for DuPont and Dow Chemical. One company held the patent for 134a and the other for R12. Whichever one made 134 started tried to buy the R12 patent and was refused. They began operating behind the scenes and got an R12 ban included in some pending environmental legislation.

So now we're all inconvenienced with crappy a/c systems that don't work as well, and big-business still gets a pass and can keep buying and selling carbon credits and pumping out exponentially more ozone-damaging gases at a single factory or power plant than every automotive a/c system could combined. Pure insanity.
 

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air conditioning problem

hi there im in need of a lil help I just purchased a 1990 300sl and went to check ac to my surprise not working I check and found that it have a blown fuse replaced it and nothing happens its got a new system put in with r134 a new a/c control due to broken one before good fuses and still no power need help thanks :confused:
 

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2005 SLK350, 91 300SL with Pano Top, 04 S500, 2015 Tesla Model S
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Put a pressure gauge at the low side. if 65 lbs or over then check for voltage at the pressure switch located at the top of the drier - the one without the pigtail connectors. If you have voltage, then try bridging the two connectors to start the compressor clutch. Most likely then you would have a bad pressure switch. They are quite cheap but you will have to drain the system in order to change it.
 
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