dash wiring rookie!

[70xlt]

I did rebuild and posted this question b4. 1970 F100 XLT, I can't get the gas gauge, interior light off and heater fan to work properly or at all. Replaced wiring circuit board, new door jamb switches, I think I checked all the grounds and went junk yard to replace the fuel tank gauge. The fuel gauge is the most important, it worked off and on for while but none now, interior light will not go off, the heater seems to have different power feed to it cause when bypass the fan works, am radio not hooked up. I have the fuel cell ground wire and the 2 wires on steering column on clean paint free grounds, are there any other grounds I'm forgetting? I used tester to make sure I have power to the cell and interior lamp. I'm a senior rookie and have no clue how to repair. I think I've checked all the wires visible for breaks etc. Any suggestion would be appreciated.


thanks 70XLT