1999oldsmobile bravada won't go into park - Cars & Trucks

one of the known with the bravada-trailblazer-and envoy was the vinal/leather boot cover on the shifter getting jammed and your vehicle also has a park release lever under the boot as well https://www.manualslib.com/manual/654367/Oldsmobile-Bravada-2002.html?page=92 tells how to get out of park --check the trans cable and linkage for damage after releasing shifter

under the floor shifter

Sounds like a short in the socket or a bad ground.
The parking light is one circuit and the brake turn signal is another.

Rusted Parking Brake Cables -- won't release if used

Internal rust in Wheel Cylinder or Caliper --from not
changing Brake Fluid every 2 years

Improper Brake Work

Pretty simple device,not that hard to diagnose

What has been done so far,in some detail

u broke the parking paw in the trans...this repair needs to b done at a service station

ck the shift linkage to the trans

check your park locking fuse

To test 4 power at the fuse the key&headlight switch on, then test4power at fuse... if you have power there then test at parking light socket 4 power&grownd

Safety interlock switch sounds bad.

battery is dead, battery cables are loose, or your vehicle is not in park all the way. Put it into neutral and try to start it there.