AC problem
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AC problem
Good Morning....I know there is an AC forum somewhere but couldnt locate it so I hope someone out there might be able to help. I recently purchased an 88 diesel, the 7.3 non turbo IH... in great condition, very low mileage...The AC isn't blowing cold. It was converted to 134a at the dealership in 2000, a nice job, all the right connectors, labeling etc. I first introduced a combo oil 134 2 oz ea , the compressor kicks on during low pressure, the pressure rises pretty quickly ( 5-6 seconds) to abt 45 lbs where it apparently trips a HP switch and cycles off, the pressure drops just as quickly and the compressor cycles back on - this continues..... The truck hadnt been driven much the last few years - there are what looks like shut off valves on both hi and low side on the compressor - it occured to me that maybe they were shut off in an attempt to retain refrigerant but Im interested in some opinions before proceeding further...
feel free to ans here as well as email directly smit9759@pacificu.edu Tks. Hugh
feel free to ans here as well as email directly smit9759@pacificu.edu Tks. Hugh
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Joined: Jan 2005
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Cooling, Heating, Ventilation & A/C - Ford Truck Enthusiasts Forums Here is a link to the A/C page.
Check out the IDI page also for great engine info.
Check out the IDI page also for great engine info.
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Joined: Jan 2006
Posts: 566
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From: Mobile, Alabama
Not knowng the prior history of the system it will be hard to help you diagnose the problem but it sounds like it was not operating and you added an oil/134a combo. Most probably you are low on refrigerant causing the compressor to cycle as stated. There are pressure switches intact to prevent the compressor from running under a low refrigerant condition as it will destroy the compressor.
You really need to know why there is no refrigerant as it will not just "naturally leak" so you will need to get a set of A/C manifold guages on it that will read both low and high pressures then introduce a small amount refrigerant and determine with a leak detector where the leak is. Once it is repaired you would need to pull a deep vacuum and recharge with the proper amount of refrigerant to get you going.
Also, unless you have an aftermarket system, there are no "cut off" valves on the compressor. That year model original compressor should be a FS6 with no valves.
Here is a great website that you will find a lot of help in repairing/diagnosing your problem.
http://www.autoacforum.com/
You really need to know why there is no refrigerant as it will not just "naturally leak" so you will need to get a set of A/C manifold guages on it that will read both low and high pressures then introduce a small amount refrigerant and determine with a leak detector where the leak is. Once it is repaired you would need to pull a deep vacuum and recharge with the proper amount of refrigerant to get you going.
Also, unless you have an aftermarket system, there are no "cut off" valves on the compressor. That year model original compressor should be a FS6 with no valves.
Here is a great website that you will find a lot of help in repairing/diagnosing your problem.
http://www.autoacforum.com/
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