I just fixed a 2002 Dodge Neon that would not shift up it was stuck in low gear replaced TCM now trans is working fine
The problem is the reverse light switch. It is located on the top of the transmission that should sloved your problem.
i cannot shift from 3 to reverse my cable line for the shifting is disconnected and don't know where it suppose to go
Is it an automatic? Time for a new transmission... If a stick and 1st, 3rd, 5th are ok, then you have a possible shift cable problem. You should be able to see them on top of the trans. If everthing is moving properly the trans has an internal problem.
I would look on the transmission by the gear shift linkage.
Shift linkage broken or misadjusted?
Try bypassing the reverse light switch that plugs into the transmission. If your reverse lights come on, voila! Problem solved. Buy a new switch.
Loose hold down clamp or broken shift cable.
Sounds like a problem with the idler gear in between the reverse gear and the layshaft.
The shift censor could be going bad. There may also be a problem with the transmission linkage which would cause this problem.
Check your fuses
the only problem that you can repair yourself would be with the linkage. but if all other gears work except reverse then the problem is probably internal and should be inspected by a professional. it makes a big difference if the trans. is manual or automatic also.
I had a similar problem where it would shift into reverse or drive but not go immediately. Or sometimes it would drop out of gear and you'd have to rev up to get it to fall back into gear. i replaced the transmission filter and it fixed the problem.