97 Tahoe Sport Liftglass wont lock

[lastson]

Hi guys/gals. New to the board, new to Tahoe's (well owning one). Just bought a 97 Tahoe Sport have been wanting one for years and finally found a great deal on one. Has a few little things to fix, door handle on drivers side is broke gotta fix that this weekend. Biggest pain is the rear tailgate/liftglass. The liftglass will not latch and secure. It will open no matter how hard you try to shut it. The tail gate opens and closes fine no issues except the keylock wont turn left or right with the key in. I have no idea where to begin to start trouble shooting this as this is my first truck/suv. Any help would be awesome!