So i put a 5.3 4l60e in my 83 c10. Everything works great other than the transmission. Since i got my truck up and running the transmission has been in "limp home mode". I was wondering if anybody had any suggestions on where to start. I've replaced the vss and the nuetral safety switch box already and the trans has been rebuilt. I've done a little research and got overwhelmed with the results on what could be wrong. I was hoping someone has had the same problem and could give me any advice. Thank you

 

Check power to the transmission at the case connector. Do a search for my old build thread. I had an '86 C10 with a 5.3L/4L65E combo. I may have posted pinout pics. I gave most of that stuff to the new owner when I sold it last year.

Did you graft your own electrical harness, or did you pay for a plug & play harness?