Its the interlock solenoid on the Tcase. The transmission needs to be in N or P and your foot on the brake. My suggestion it to pull the solenoid and don't look back.
Its under this plate. Pull the 4 bolts, there is snap ring holding the solenoid in place, pull it and the solenoid. then get 'the right stuff' and reseal the plate.
The offending bastard.