When you say, "...working on the passenger side", do you mean only blowing cold on the passenger side or not blowing at all on the driver side?
If it's the former, have the system checked for proper charge level by a mechanic. These systems are known to leak down over time causing first a no-cold on one side then no cold at all condition. If the system is low on refrigerant, the compressor may not kick on at all.
It is possible that this is a case of a bad compressor clutch (do a search for that), but start with a proper diagnosis of the charge.
If it's the former, have the system checked for proper charge level by a mechanic. These systems are known to leak down over time causing first a no-cold on one side then no cold at all condition. If the system is low on refrigerant, the compressor may not kick on at all.
It is possible that this is a case of a bad compressor clutch (do a search for that), but start with a proper diagnosis of the charge.