I bought truck used a year ago with new transmission. Has been working fine until last month. When in drive, it wont shift gears. When in 2nd gear position, it will shift from 1 to 2. After its in 2, if i shift to drive, occasionally it will go to 3 but very rarely. If it goes to 3 it goes to 4 fine. For the first 5 minutes of being on after sitting all night, transmission works fine throughout all gears. I took to mechanic to look at, He checked all sensors, fuses, electrical, everything he said he could check outside the transmission. My Govener sensor gave him a bad reading so i chose to change it hoping it would fix($188). Still nothing. A week later check engine light came on, so i took it back, Code was 1736- govenor sensor/selenoid number 7/pressure to sensor too low, so he rechecked sensor and did a test on selenoid, couldnt find a problem. Mechanic says transmission is getting all proper signals to switch, but just isnt doing so, he also said my oil pressure seems good being that it goes right into reverse and drive. I have the correct fluid, my screenFilter is clean, no loose wires, nothing obvious.

The same day the transmission stopped working, The interior lights that come on when door is opened, or unlocked with keyless remote, stopped coming on. I can turn on the interior lights manually by pushing then on one at a time, but with the dimmer switch way of doing so, nothing.

I know it sounds crazy but can these 2 issues be related???
Or does anyone have any ideas to make my trans work again???
Please help me.