electrical issues bad
 

So my truck last week decided to stick in 3rd gear so took the valve body out found the govener pressure sensor was toast so got a new one put it all back together and truck still stuck in 3rd so we tested all wires and fuses all good and then we found out when you first turn the key on I have my 12 power goin to trans for only about 15sec. Can you guys help me out?:s: these are the codes I'm gettin P1681 No mic Bus P0748 gov press P1693 mil fault. Is it my computer?

swap your trans relay see what happens. check all connectors on trans . code p1693 means there is a code in another computer. p1681 dont know . p0748 means governor pressure solenoid control/trans relay circuits. try the trans relay swap if that dont work check your connectors and connections really well