Freon low, how to bypass pressure switch so I can add freon?

1998 Olds Intrigue, low on freon. The pressure switch has the compressor turned off. How do I bypass it so the compressor will run and I can add freon?

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A 98 Olds Intrigue wouldn't use "Freon."

Probably for a very good reason.

The compressor doesn't need to be running in order to add "Freon."
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So, what can I say "correctly" to find out how to bypass the pressure switch. Am adding 134a after compressor change and dryer change and orfice change. Have pulled vacuum down, but need the compressor to engage so I can pull more 134a (not freon) into system. Do you know how to do this?
wrote:

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snipped-for-privacy@smammotel.com (Jim March) wrote:

I doubt there's anything.

Well good. from the sounds of things initially, you were about to add the wrong refrigerant.

Engaging the compressor will not "pull" more refrigerant into the system.

Yes I do. It is done by making the pressure inside the vessel of refrigerant higher than the static pressure in the vehicles AC system. If the static pressure is not high enough to close the low side switch, there isn't yet enough refrigerant in the system to carry the necessary lubricant to avoid a compressor failure. (you do know that the refrigerant carries the lubricant, don't you?)
To raise the pressure inside your charging vessel (jug or can) you need to heat it up. Hot water usually will suffice. It will be a little slow, and you'll no doubt need to make numerous trips to replenish the hot water to accomplish what you need, but thems the breaks when you don't have the correct equipment.
Say "thank you Neil" because I just saved you from screwing up your brand new compressor.
Sorry if this sounds a little terse, but these systems are so damn fragile that if you don't follow proper procedures, they tend to be very short lived.
Oh yeah... I hope you used the correct oil in the correct amounts and distributed it into the correct components in the proper proportions, unlike another poster in a different group.
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Ok. So, I guess I could just plug in my charging cylinder to push the 134a in then. About the oil, I added 8 oz to the compressor and 2 to the orfice.
Any more advice before I say "thank you Neil"?
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The total oil capacity for the entire system is 8 ounces.
8 ounces inside the compressor is an awful lot...
I'd have put 2 ounces in the compressor, 2 ounces in the evaporator, 2 ounces in the condenser and 2 ounces in the accumulator.
At this point, you should attempt hand turning the compressor to make certain that it's not hydraulically locked before you apply power to the clutch.
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But, I am curious, if I wanted to charge the system using gas instead of liquid, how would you do that without the compressor running?
wrote:

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With the can stood upright, gas will be discharged, invert the can (tapper down) and liquid will be discharged. If recharging via a 30lb jug, it's vice versa.
In the inverted state, if ambient temperatures are high enough, by the time the refrigerant reaches the low side service port, it'll probably already have changed to gas.
When refilling the system via the low side service port, you DO want the refrigerant to be in a gaseous state. The low side of the system is the inlet to the compressor and compressors of this type do not tend to handle the intake of liquids very well.
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Thanks, Neal. I read some more and finished the job tonight. I replaced the compressor, due to bad bearings. I added 9oz (per specs in manual) 150 visc. oil. I took it down to a vacuum 29 +- 1 for 35 minutes, let it stand for 5 minutes. No leaks. On the high side, I used a charging cylinder. Measured in 1.9 lbs of liquid. I then released it into the high side until it slowed, then plugged in the cylinder heater and emptied it into the car. I let the car sit another 15 - 30 minutes while I reinstalled air filter etc. Started engine, clutch engaged, pressures were as in the spec sheet, and all is well. I used to help my dad in his garage years ago using freon, and we had to bypass the pressure switch to get the thing to take freon WITH the engine running. I just assumed the same went today. Actually, had I not had access to the charging cylinder, I would have had to force the freon in to the low side as a gas somehow, I thought. Well, thanks again for your fine advice. Jim
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unplug the pressure switch and get a piece of wire and put it in the pressure switch touching both contacts in the switch that will make the compressor run steady.

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I did that nad it didn't work. There are 3 wires going to the switch that is on the llow side line.
On Tue, 11 May 2004 15:22:41 -0400, "Mike & Chris"

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In all seriousness, this is a dangerous task. You could be injured or killed. I am reluctant to provide information that could injure or kill you if used incorrectly. By bypassing the switch, it is possible to put so much pressure on the refrigerant cylinder that it bursts.
I become increasingly suspicious that you don't really understand the workings of the system and should have it serviced by someone who is more familiar with a/c systems and how they work.
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Jim, I agree with this answer. I am also wondering how you added 2oz of oil, PAG oil I trust, to the orfice tube? It should have been added into the accumulator. Do you know for sure that the total oil capacity is 10oz? Are you using a gauge/manifold set to do this refridgerant charge?
Dave S(Texas)
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Never mind. On Tue, 11 May 2004 18:21:48 -0500, snipped-for-privacy@webtv.net wrote:

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Go have the code cleared. Once you get a low refrigerant code, the compressor will not turn back on until it is cleared. It will not engage the compressor clutch relay and for good reason. Do not turn the air back on after having the code cleared until you have the 134a hooked up to the valve.
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Amen!
An asshole with a can of refrigerant in his or her hand, may very well soon become a dismembered and dead asshole, with an exploded can of refrigerant in their missing hand!
Heat the can, to raise the temperature of the gas in the can, in a can of hot water from the tap, and you'd be surprised how fast it goes in the high side. With the engine off!
Refinish King

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