AC Problem - tried searching. please help

[xkrisx]

Alright first off I have a 91 240sx ka24de and it has 167k miles.

Problem 1:I recently got it converted to r134a and my friend charged up the system and it ran perfect, but when I switched it to the max power (number 4) the AC turned it self off. The compressor clicked off and the light went out on the AC and it was just the fan blowing, then we switched it back to 3 and it worked fine.

Problem 2:After driving around the block we decided to see if the AC would hold the charge so I switched it off and then back on but it was warm and wouldnt get cold (I tried giving it gas/driving around, but still didnt get cold). I'm thinking I should replace the compressor for this problem but I wanted a second opinion.

Thanks

-kris

[JeromeS13]

There's a chance that its the actual climate control unit. There should be a step by step troubleshooting section in the FSM. Give that a shot and get back to us.

[xkrisx]

Gonna check the FSM now, thanks for replying

[kris nissan for life]

hey is your name relly kris wiht a k me to lol i will look in my book about the ac thing

[amolao]

If you just did the conversion from freon, I think you migh had some contamination in the system for a while. Check for leaks.....and if you are not building pressure enough to get a green "AC button light" then your comp is gone...I bought a rebuilt one on Ebay with warranty and still running years later....

[nukeone]

Problem 1: I recently got it converted to r134a and my friend charged up the system and it ran perfect, but when I switched it to the max power (number 4) the AC turned it self off. The compressor clicked off and the light went out on the AC and it was just the fan blowing, then we switched it back to 3 and it worked fine.

Fan speed setting should have nothing to do with compressor operation. Compressor operates if the A/C button is depressed, IGN is on, and the fan is on (any position) but only if the dual pressure switch senses proper pressure (not too high, not too low).

Problem 2: After driving around the block we decided to see if the AC would hold the charge so I switched it off and then back on but it was warm and wouldnt get cold (I tried giving it gas/driving around, but still didnt get cold). I'm thinking I should replace the compressor for this problem but I wanted a second opinion.

Easiest check is to recharge and see if it gets cold again. That tells you that the compressor is OK but doesn't hold a charge. If pressure is not correct, the A/C light will not come on. Can you hear the compressor clutch pull in when you switch it on? For testing the compressor, you can bypass the switches (including the pressure interlocks and temperature control amp) by taking 12 V directly to the compressor signal wire connector and verifying the clutch pulls in. You can do this with the car not running, so you can hear the magnetic click. If the clutch pulls in, and you get cold air, the compressor is OK. If it doesn't, either the compressor is bad or you have a serious refrigerant leak. If you determine the compressor is OK, then you can begin troubleshooting the temp control amp, fan speed resistors, A/C relays, fuses, etc. Yes, it can be an exhaustive search!