Air Condition Low pressure side
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Elk Grove CA
Air Condition Low pressure side
I'm planning to service my 1975 Vett AC, they are three connectors and all the same fittings. One behind the compresor, one bettwen pipe with sight glass, and one above the accumulator. Which one is it?
Thanks,
Art
Thanks,
Art
Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: Air Condition Low pressure side (bluebelVETTE)
The one on the accumulator should be the low side. The one at the sight glass would be the high side.(liquid line)
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: Air Condition Low pressure side (bluebelVETTE)
Stay away from the one between the pipe and site glass. You should really use gauges so you can service it correctly and not get hurt doing it.
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Elk Grove CA
Re: Air Condition Low pressure side (Larry B.)
What about the one behind the compessor where the connector attach to the compressor? It is easy access compare the one above the accumulator. I think the one behind the compresor is a low side also because it is sharing the same connector that goes to the compressor and the rubber hose attached to it is not compressed or hydraulic style type hose, just a hose clamp. If that is a high side I don't think they would use hose clamp.
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Elk Grove CA
Re: Air Condition Low pressure side (bluebelVETTE)
I have put a gauges on the connector here is my reading.
The one behind the compressor the reading is 75psi, the one between the tubing with sight glass reads 20-30psi. Currently the compressor is not turning when I turn on the AC could it be the pressure too low?
What are the correct reading?
The one behind the compressor the reading is 75psi, the one between the tubing with sight glass reads 20-30psi. Currently the compressor is not turning when I turn on the AC could it be the pressure too low?
What are the correct reading?
Burning Brakes
Joined: Jan 2004
Posts: 868
Likes: 2
From: Olney MD
Re: Air Condition Low pressure side (LAvetteman)
The one on the accumulator should be the low side. The one at the sight glass would be the high side.(liquid line)
Safety Car
Joined: Jan 2001
Posts: 4,660
Likes: 3
From: South Central Louisiana
St. Jude Contributor
Re: Air Condition Low pressure side (1FUNVET)
The one on the accumulator should be the low side. The one at the sight glass would be the high side.(liquid line)
:nono: The low side is the liquid line.
:nono: The low side is the liquid line.
I' am not 100% sure about many things, but this I am. I spent 2 years in technical college and 10 years in the field. ;) :nono:
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Instructor
Joined: Dec 2002
Posts: 242
Likes: 0
From: Port Orchard Washington
Re: Air Condition Low pressure side (bluebelVETTE)
When the compressor is not running the system reaches an equilibrium - high and low sides will nearly equalize. Your pressures are showing a blockage or shut valve that should be open. Also with your pressures the compressor clutch should engage. Remove the electrical connector at the clutch and put a meter on it. If you are not getting 12v when the controls are turned on at the console, work back from there.
Cruising
Joined: Oct 2003
Posts: 10
Likes: 0
From: Emmett ID
Re: Air Condition Low pressure side (Missileman)
Just ready this reply and I have similiar issues. Have a 79. Could you tell me where I can find the site glass and why I don't have power there? I have power going into the outlet_(high valve?) but not coming out to the temperature sensure. Can you help?
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Elk Grove CA
Re: Air Condition Low pressure side (Missileman)
I've checked the power source and find out that the pressure switch connector is bad, so I put a jumper and the compresor started. I let it run for a while the air still not blowing cold air. I've checked the AC pipe I can feel the the pipe is very cold and the line going to the compresor from accumulator is freezing, but still no cold air. Does it need charging or what?
What else I need to check?
Thanks,
Art
What else I need to check?
Thanks,
Art
Instructor
Joined: Dec 2002
Posts: 242
Likes: 0
From: Port Orchard Washington
Re: Air Condition Low pressure side (Sapas)
sapas:
I don't believe a sight glass is on a 79. The system was protected from running while low on freon by the low pressure switch on the accumulator.
I'm not understanding your question, so I'll explain. Power comes from the control in the console to the low pressure switch. If accum. pressure is high enough the contacts are closed and sends power to the clutch, then to ground. If you jumper out the switch and your clutch engages, it means that either the switch is bad, or the system is too low. Either way you need to have gauges connected when the switch is jumpered.
I don't believe a sight glass is on a 79. The system was protected from running while low on freon by the low pressure switch on the accumulator.
I'm not understanding your question, so I'll explain. Power comes from the control in the console to the low pressure switch. If accum. pressure is high enough the contacts are closed and sends power to the clutch, then to ground. If you jumper out the switch and your clutch engages, it means that either the switch is bad, or the system is too low. Either way you need to have gauges connected when the switch is jumpered.
