no lock up(pretty involved) help!!!

[PhatGN]

i installed a FAST on car so i am hard wiring the tcc solenoid. i have power going to A the tcc solenoid(just pulled pan off to verify) if i ground D the solenoid clicks but seems weak but i have never checked another one, while driving on the interstate i would ground the tan/black D wire and wouldn't lock up also never got any kind of a signal from pin B (4th gear switch) i have been reading and the 4th gear switch is a one wire and most say it needs a two wire switch??? regardless if i directly ground the neg side of the solenoid it doesn't lock. the speedo isn't working but at this point that cannot effect the tcc since i am hard wiring it.
while i got the pan off is there any other troubleshooting you can suggest

thanks

 

[PhatGN]

Alright I checked the valve above the tcc solenoid, it moves up and down freely, so you think the solenoid sounding weak might be the cause of no lock up? Really want to put this thing back together for the weekend, anyone know a place to get a two wire 4th gear switch

 

[SSedan64]

Weak ground or solenoid. A GM dealer or Trans parts house should have the 4th pressure switch. There's several Part#'s at the bottom of the page on this site. >> Automatic Overdrive Transmission Swap