AC only warm air is coming through the vents

Not sure if I'm too late to answer this one, but you're describing a low refrigerant condition. The hissing noise and constant cycling of the compressor clutch are indicators of that. You should recover the system, record how much refrigerant was recovered, evacuate the system (with a vacuum pump), add A/C dye, and recharge the system to capacity. Common leak areas on these vehicles include the A/C condenser (located in front of the radiator), and the evaporator (located inside the dash, and requires complete removal of the interior dash to replace it). If you can't find a visible leak after running the recharged system with dye for several weeks and it starts to blow warm again, you will need to use an R-134a leak detector to "sniff" areas of the system for a refrigerant leak.

replace the electronic components

best diagnostic method is dual head gauges. balanced pressure between low and high side in the off position is aroung 90 lbs. running low pressure is 20-40 lbs and high pressure 160-200, is the compressior not coming on? does it stay on, or click on and off. either might mean the freon level is low. try unplugging the low pressure switch on the low side supply line and shorting the pigtail wires together with a paper clip. does the compressor stay on now? if so and the air is warm or cool, freon is low. if the air is cold that switch is bad. if compressor still won't come on the list of possibilities grows longer: compressor, comp fan clutch, AC relay, restriction at several places... repair shop time...

That's the symptom of a system that's low on refrigerant or has a bad pressure switch

Are you using gauges?What are the pressures?And are the cooling fans coming on when ac is on?

you may have a bad oil filter, the best check is to install an oilpressure guage to find out what the actual pressure is, or maybe you put in too light an an oil,

on the low side 35-40 psi. you really should charge by weight, then you KNOW its got the correct amount in. the way to partial charge is feel the inlet pipe and then the outlet, when the charge is full, they will be the same temp.

I'm not sure if I understand you correctly. Does the air conditioning works properly it's just the sound problem and did it happens suddenly?
For the strange sound, it could be normal and not.
I imagine the sound comes from the exchange pressure between the low pressure and high pressure.
To fix or knowing what is wrong you will have to get AC/pressure gauge install on AC/pressure tap under the hood and sync the compressor engaging clutch if it happens at the same time that the sound you are talking about.
Pretty hard to tell online without earing it. But I ever listen to a sound similar to that.

hope it helps

recharge to 25 to 40. it should be low in freon

THE 1ST THING U DO IS VERIFY THE SYSTEM IS FULLY CHARGED, WHAT IS THE LOW SIDE LINE PRESSURE? SHOULD BE AROUND 28 PSI WHEN COMPRESSOR IS ENGAGED.