Is this normal when re-gassing A/C?
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C240 4MATIC
Is this normal when re-gassing A/C?
I tried to re-gas my A/C yesterday. When I hooked up the gauge, it read 0 psi. When I started the car with the air on cool, still 0 psi. I sprayed the can for no more than 3 seconds, it shot to 45 psi. Is this a sign that my AC compressor is not on? My car's A/C on light has been red since I bought it. I've read that if it's off, I should add half a can of freon. Should I continue adding more freon?
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From: Finland, Europe
W203 C200CDI
You are saying "A/C on light has been red since I bought it", do you mean the button "AUTO" with this? Red light means a/c is on and working.
If your EC button is red and wont go off, then you are running low on gases or have some other problems with a/c.
Is your a/c is working properly or not?
If your EC button is red and wont go off, then you are running low on gases or have some other problems with a/c.
Is your a/c is working properly or not?
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C240 4MATIC
No, I do not have the "E/C" button. I have the "A/C" button instead in this model. & no, it does not go off. I've read if you run out of freon, this light also comes on. But it can also come on when there's other problems as well. No, my A/C is not working. It hasn't worked since I bought it.
Last edited by blzdout; May 10, 2014 at 11:43 AM.
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From: Northwest Arkansas
2016 C450
Sorry, you cannot properly charge your system with parts store cans. You need to vacuum down the system to get all the air and moisture out, and you need it charged with a precise amount of refrigerant. You then need to clear the faults in climate control.
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C240 4MATIC
Yeah I kinda figured. Going to have to take it to the stealership in a couple weeks 
they want $120 just to diagnose the problem. I was going to just take it to a regular a/c shop but Idk. Could a regular AC shop diagnose this kind of problem or should I just take it to the stealership?
they want $120 just to diagnose the problem. I was going to just take it to a regular a/c shop but Idk. Could a regular AC shop diagnose this kind of problem or should I just take it to the stealership?
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From: Austin, TX
2005 C230K(sold), Mk7 Jetta
It's possible to jump the compressor from the battery (bypassing the low pressure protection).
You can rent the vacuum pump and the AC manifold gauges from Autozone.
Just need to figure out how much refrigerant it takes and go from there.
After that you will probably still need to clear the codes in the climate unit(?)
You can rent the vacuum pump and the AC manifold gauges from Autozone.
Just need to figure out how much refrigerant it takes and go from there.
After that you will probably still need to clear the codes in the climate unit(?)
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From: Toronto, ON
2012 C300 Sport 4MATIC (current) 2006 C280 Elegance 4MATIC (sold)
Go to an independent mechanic or any shop for that matter that has good A/C equipment. Do you see your A/C compressor pulley in the center spinning when you press the button? Also, if your system needs re-gassing then that means you have a leak and that needs tending to first since these systems run constantly when the system is on vs. clicking on and off.
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From: Northwest Arkansas
2016 C450
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c240
Is there a way to tell if the compressor is working or not if the pulley is always turning? My system is fully charged (about 40 psi) but it's not sending cold air, it's just cool air.
Also, can you add oil to the compressor (PAG46?) directly, because I think it's leaking oil but not refrigrant?
Any help is appreciated..
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From: Toronto, ON
2012 C300 Sport 4MATIC (current) 2006 C280 Elegance 4MATIC (sold)
Yep I learned something new. When I was buying my car last year I looked at the AC compressor pulley and when I saw it spinning I thought it was working as it should but that's not an indicator that it works. It blew cold though and the low pressure line was cold and wet. It would suck if this type of compressor broke because it's more expensive though it engages so smoothly it's impossible to tell. My previous car would jerk every time the clutch kicked in.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Have the system checked for leaks & regassed by a Pro.
Older cars had the A/C switch light on when the system was off. Newer cars have the more intuitive light on when the system is on.
If low gas pressure is detected by the pressure/temp sensor in the front Condenser the A/C will not run to protect the compressor.
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late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
No ~ some oil could be lost with the refrigerant but you should see it.
The compressor won't run without correct refrigerant pressure. You have to pressurise the system before you can check anything.
The compressor won't run without correct refrigerant pressure. You have to pressurise the system before you can check anything.
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From: Austin, TX
2005 C230K(sold), Mk7 Jetta
C240,
You can check if the compressor is engaging if you connect a manifold gauge set to the lines - should see the pressure rise and fall when the AC is on. You can google the approximate high side/low side pressures.
This way you'll also see if the static pressure (AC off) is too low and the car does not let the compressor turn on.
You can check if the compressor is engaging if you connect a manifold gauge set to the lines - should see the pressure rise and fall when the AC is on. You can google the approximate high side/low side pressures.
This way you'll also see if the static pressure (AC off) is too low and the car does not let the compressor turn on.
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c240
VVF,
excellent timing. I just purchased the HFT manifold guage set. I was going to ask what the high pressure should be. I will google around.
This morning I checked the temp coming out of the vent and it between 53-60F. Outside is 75. There should be more of a difference I think.
Thanks for the reply.
excellent timing. I just purchased the HFT manifold guage set. I was going to ask what the high pressure should be. I will google around.
This morning I checked the temp coming out of the vent and it between 53-60F. Outside is 75. There should be more of a difference I think.
Thanks for the reply.
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From: Austin, TX
2005 C230K(sold), Mk7 Jetta
Do you know who had recharged the system? AFAIK the low pressure could be 40psi but there might be not enough refrigerant so as to achieve full effectiveness.
Anyway, the low/high side pressure readings and the frequency of the compressor on/off cycling will indicate that when you test.
Anyway, the low/high side pressure readings and the frequency of the compressor on/off cycling will indicate that when you test.
