my 240sx has some problems :(

[RacerfreakXXX]

I'm having some problems hopefully you guys can help:

I have a 92 140sx coupe auto converted to manual trans w/ ka24de

1st - temp gauge isn't working, sender and temp sensor has been replaced and gauge worked when there was an sr in the chassis and so far the doesn't seem to have overheated from what I know. Whats the best next step to finding out whats wrong? (All I can think is its the wiring in the harness, want to see what else it could be.)

2nd - clutch just drops down to engagement point and doesn't come back up unless I pull it, trans chatters in 1st and 2nd and also grinds into second. whats the issue/ solution? (I was thinking it could be the pivot ball or the bearing idk???) My original issue was that the clutch was engaging right after pushing it in an inch, literally. I check the clutch and saw there was a bolt stopping the clutch from coming forward (clutch looked sunken in compared to the brake pedal), removed it and now I have my current problem.