2 questions

[jasonroman]

cant get the radio to keep presets
have a wire running to fuse box which i thought would be constant. to keep presets and such. but its not working.
everytime i shut off truck. power is lost. presets go out. and then when i start truck again. i need to power up radio????

wouldnt the wire run from fuse box at radio fuse. be the constant? or is that power??

then i hooked up a tach. and ran the white wire into fuse box. i think at the guage fuse.
and now my interior lights dont light up??

any help is much appreciated.