Limp Mode
 

I got a 98.5 24v PPumped truck runs excellent but when put into drive its in a limp were it wont shift out of second gear just revs up, I cannot manually put it into first gear either. Im getting a code for speed sensor in the rear end so I will investigate that. Also when I got the truck it was a 5 speed kid converted it over was a wiring mess, and sometimes it wouldn't downshift into 1st gear at all, when we got to a stop sign the kid would throw it in neutral turn key back then back on real fast to reset the computers? and we would be off again and truck would run fine and the truck had lockup and all, it sat for aewhile then I decided to take it out and now it wont shift at all its stuck in a limp. Ive brought it back to the guy who built the tranny and he is very good he tested the selionids and he said hes getting 12v down at them when there should only be 5v were are the ground locations?