You should probablly have the system pumped down and recharged with new freon it could be showing a good reading but still have a restriction in the system that is not allowing the gas to flow compleatly through the system. i am a certified refridgeration tech. good luck i had the same problem on my 98 s 10, in fact i just fixed it myself last night! if you have the 2.2 liter engine: they run the wires for your electomagnetic clutch on your compressor, through your intake manifold, under your airbox(the one just before your throttle body) and while it is under your airbox it is lying ON THE CYLINDER HEAD and after a few years the tape and snorkle tube protecting the wires may have come loose, and then the heat from the cylinder head melts the insulation off of the wire, and ending up in a short circuit, which blows the 10 amp. fuse (which is located in the relay and fuse box on the driver side under the hood. the first thing you need to do is start your truck and put your ac on max ac and the fan on 4 now pop the hood and go and see if the clutch on the fan is spinning (i bet you it isnt) now to check and make sure the compressor and the clutch are still good, unplug the wire that connect to the compressor, and run a hot wire from your battery to one side of the connector that is on the compressor and the other side of the compressor connector to ground. it you hear a pretty loud click and you see the clutch plate pull in and out as you add and remove power you are looking pretty good, now leave power running to the compressor and start your truck, turn on the ac and if your compressor is still good your ac should be working! take a pressure reading on the low pressure side(which is on your condensor) while you have it hot wired. it should be in the perfect range, if it is a little low like mine was , just go down to any auto part store and buy a refrigerant recharge kit( about $20 for the one with a built in guage) and fill it up to the correct pressure, im sure that you know that you have to have the truck running and the ac on full blast while reading pressure or filling it back up! ok now if everything is working properly you need remove the air box mentioned earlier and check your wires( while you are checking those you might as well check them all that run over the cylinder head there are a total of 5 sets that run that way) if the insulation is melted dont just recover it and call it good, cause the integrity of the wire is now broken down. instead cut the bad section of wire out and splice them back together, be sure to replace the diode, cause the chances of it surviving a short circuit like that are slim to none( the diode is in that small box that is clipped around the wires) after you have spliced them back together make sure that you insulate all of the wires running that way from the heat so it wont happen again. now replace the 10 amp fuse and start the truck and the ac should now be working! if so you just saved your self about $300, congadulations!oh yeah put the air box back in, and if you look inside the air box in the side that goes back to your filter, not the side that goes to your throttle body. there will be a removable plastic sleeve inside, pull that s.o.b. out it is restricting a lot of air! now put the air box back in! ! oh yeah i forgot to answer your actuall question! the reason you were reading such a high pressure was because the compressor clutch was not engaged, so your ac was not really on! which it needs to be in order to get an acurate reading. the other guy who helped you was a refriration technician, he may be able to tell you in exact detail why it works that way, i just know it does, and im just a union electrician!
Well rather than run a hotwire from your battery, a piece of copper wire to jump the connector to the switch works.
The low pressure side should only read 30 to 45 psi. You have a restriction. My guess would be an orifice tube plugged up with trash from a failing compressor.
in my mouth
in the Chevy Malibu forum
I beleave it is suppose to be 45.....I think.... I saw it early today
It really needs to be checked out but it probably is the blower votor.
The 2004 Chevrolet Impala air conditioning pressure switch can be found on the end of the air conditioner compressor. The pressure switch should be labeled as such.
Not sure what your asking yes you charge from the low pressure port it is the smaller one your hose should not fit on the high pressure side
If a 88 Chevy Pickup Truck seems to be low on power the timing should be checked. The fuel pressure and fuel pump should also be checked and may be the source of low power in the vehicle.
If it is injected you might not be getting enough fuel pressure. Check fuel pressure regulater
schematic of 1998 chevy lumina ltz 3.8l air conditioner
You may have some fuel pressure but not enough. Do a pressure test with a fuel pressure test gauge, it should have 41 to 47 psi to properly run the engine. Sorry, But that engine should have 9 to 13 LBS. of fuel pressure. No lower are higher are you will have problems.
Low pressure connector is at the front of engine below front exhaust manifold behind the electric fan for the rad....
Your 1989 Chevy truck air-conditioner condensation drain can be found on the bottom of the air conditioner compressor. The air conditioner condensation drain routes condensation to the bottom of the engine compartment.