when i turn off the ignition key on my jimmy, it wouln't go all the way back, and i had to push a button under steering collum to get key out... (car would cut off, just couldnt turn key all the way back),,,,, i thought it was the key cylinder and ignition harness inside the steering collum,,but it turn out,,,,it was a switch/harness on the gear shifter...... so before you tear into steering wheel,, you may be better off taking it to mechanic and let them figure it out and check the gear shifter!!! at least i can take my parts back to autozone.... it cost about 139 at mechanic to fix gear switch. good luck.
