I recently purchased a 1997 Plymouth Grand Voyager with the 3.3L engine and the Automatic 4 speed transmission. This is a project vehicle that had many issues. The dash was disassembled, the instrument cluster did not work, and the transmission would not shift into overdrive. I made progress. First of all, I resoldered the circuit board of the instrument cluster--now working. I have replaced the Transmission fluid and filter, replaced the input and output speed sensors, replaced the TCM, and replaced the Shift Solenoid pack. I used "Used "parts and regular transmission fluid. The van still does not shift into overdrive. At 50 mph, the tach shows about 4000rpm. Since I did not drive the van before making the changes, I do not know what it was doing before. So the transmission issues are a work in progress.

A new problem is the turn signal switch. Intermittantly, after driving for a period o time, the turn signals will not work. The next day, they seem to be ok. Also, the steering wheel will not lock after the key is removed. When I reassembled the dash, I noticed that there is a red female connector under the steering wheel that I cannot identify what plugs into it.

Any advice or words of wisdom would be appreciated. These seem to be good vehicles that do not die natural deaths.

 

Sounds like the transmission in in limp mode (2nd gear). If there were signs of major component failure in the oil pan when you changed the fluid and filter, the transmission probably needs to come out for a rebuild.
The turn signal issue may be a bad ground or the stalk is just worn out. Check the grounds under the battery tray and on the engine.