94 TD 4L80E stuck in 2nd

[lchapelle]

Hello, new user here. I have a 1994 2500 TD which has been giving me trouble getting stuck in 2nd gear for almost a year. I could shut the truck off and restart and the problem would go away for maybe a week or two. Then it started happening more and more and now it will not reset at all just stuck in 2nd gear. The speedometer also is not working now. I have replaced input and output speed sensors. I checked the codes using the SES light and paper clip and I get a consistent 24. I can reset the codes but when I try to drive then check again the code is back. I noticed that the transmission harness is loose because the plastic clips that hold it together are broke. Dont know how long it was that way. Should I replace the harness before trouble-shooting further? How hard is it to replace? Should I solder or use crimps that come with it? Any suggestions would be greatly appreciated.

[Jeremy-WI]

The harness is loose or the connector? If you meant the connector, you should definitely replace

[MT-2500]

First thing you need to do is get the speedometer working right.
Fix all wiring and get it on a transmission/engine capable scanner and read out data and codes.
Post back any code no.