How do you replace a ac compressor on 2003 Chevy?

Answer 1

• Have the refrigerant recovered by a certified tech
• Remove the serpentine belt (or whichever belt goes to the compressor if it's not a serpentine drive system)
• Separate the AC lines from the compressor with a fuel line separator.
• Disconnect all sensor and electrical lines from the compressor
• Unbolt the compressor
• Install the new compressor
• Bolt the compressor back in
• Think this is where you reattach sensor and electrical connectors? NO! Because you've opened up your AC system, you've introduced atmospheric air into your AC system - particularly, the accumulator, which contains a dessicant that becomes fully saturated within five minutes of atmospheric air exposure. So now you have to replace the accumulator (most Chevy models use a Fixed Orifice Tube system, as far as I know.. if yours has a Thermal Expansion Valve system, it will be the receiver-drier which has to be replaced).
• Once that's done, reattach your sensor and electrical connectors to the compressor.
• Recharge AC system, and be sure to put the proper amount of refrigerant and compressor oil back into the system (know how to measure this out? You don't? That's why the refrigerant and compressor oil should be fully recovered by a certified tech who knows what they're doing).
• Reattach serpentine belt.

The reality of it is that AC system maintenance and repair is NOT a "do-it-yourself" task... most AC problems I've encountered have been cases of DIY-ers trying to do this themselves without any real knowledge of what they were doing, and who subsequently got it wrong. I would discourage you from attempting to do such.