My o6 trailblazers gear shifter button would not depress so I could put it in gear. took the top part of the shifter of and with a little force got it to start working. when I went to turn the vehicle off the key switch will not go into the off position so I have to disconnect my battery so it don't kill it

SOURCE: 97 Celica - Key stuck in accesory position

while in park, press shifter firmly even farther above park. Hold shifter and turn key.
The linkage may need adjusting. If this does not help the situation, then the pins inside the ignition are not getting pressed down because key is getting worn. You can try to tap around the ignition lightly with hammer to shake the pins loose.

SOURCE: 97 celica - key stuck in accessory position until battery dies

adjust the shift linkage so you can put it in park

SOURCE: I have 1999 Jimmy. When I turn off the engine,

the cable they unhooked is causing this

SOURCE: 2001 Buick Regal LSE odometer and gear shifter position is not

I had the same problem with my Odometer in my 01' Regal. The dealer will quote you some outrageous price for a new instrument cluster. There are a bunch of people on Ebay that you can pay around $100 and they will repair it for you. Or, if your husband is pretty handy you can fix it yourself for about $2.00. All you need is a pack of resistors from RadioShack and soldering gun. I did it myself and with this videos instruction it only took me a little under an hour and $12.00.

As for the service light, I don't know what you had repaired, but to get mine off I had to get a dealer to reset the computer (about $100 or so).

SOURCE: I have a 2002 Chevy Trailblazer that is stuck in

Replace nutual safety switch, mounts on the side of the transmission by the shifter lever.