Why not just take it out and take it to a local A/C service place and have them repair it. If it is "made for the system", it seems it would better to use it than buy a new one, not to mention cheaper.
Joe
"Truckin' Around .......... Since 1937!" My name is Joe and I am addicted to Classic Country Music. I just can't hep myself. Operators are standing by to take your calls! Now cruising in the Passing Lane