Like I said in previous post, I even cut the green/white wire to eliminate any voltage and the white button still didn't release without some pressure.

 

Do you have a electric brake controller hooked up?

 

You said you replaced brake lamp switch? Where was switch that you replaced located?

 

No electric brake controller. Brake lamp switch was located where brake pedal lever and linkage meet under dash

 

If you have the connector at shifter(6 pin connector) disconnected and you have 8v on green white wire with brake pedal pressed the only way voltage is on that wire is either through brake switch or that wire is shorted to power somewhere. Did you put a new brake switch in or a used one?

 

Ok. But if I totally cut the green/white wire so there's no voltage on that wire at all at the connector, why won't that button smoothly release when it has no voltage??? It should work but it does not.

The other thing happening is at the ignition. If I have vehicle in park and no foot on brake the key only shuts off to the first position. If foot is on brake and engine running it will release all the way. Somehow the two things are related I suspect.

 

New brake switch. ACDelco

 

The fun continues...

Decided to replace the Neutral Safety Switch and lots of problems. First, the Shifter vs dash display of transmission gear not in sync. So I know the NSS is positioned to neutral to install. Should the tranny be in park or neutral when I install?

Hopefully once I get that in sync it will work but right now I'm not getting click on the Shift lock Switch.

 

Conclusion...I'm pretty sure the issue in the end was the Park Neutral Safety Switch. Old one had some play in it and was probably causing the Shifter Lock Solenoid to not fully disengage.