So I come home from work today and I turn the key off to my truck and it doesent turn off, then I try to start it again and I cant hear the fuel pump, then it barelly starts and then i turned the key off and It dosent wanna turn off and it acts like it wants to start when you turn off the key and the starter almost caught on fire while that was happening, i plugged in the smarty and ran codes and got these:
1693
0602
0460
0645
1687
I have no idea what those codes mean but someone please help and tell me its not major

 

How about trying our own Wiki:

http://wiki.dieseltruckresource.com/wiki/Computer_codes

 

just so it wont crank I have to unplug the battaries, I know its something with the ignition but could this be my fuel pump? or vp? 'cause when i tried cranking it I couldnt hear the fuel pump turn on, then I tried it agian and I could barelly hear it,P0602 Checksum Error, what is that?
help me out

 

starter contacts are bad..... do a search on starter contacts

 

I believe a P0602 is a fuel calibration code

 

po603 pcm keep alive memory fault

0460 fuel level sensor malfuction

0645 ac clucth relay control circut

 

That's my thought too. I'd inspect and replace the contacts, clear the codes, and go from there.