2002 T&C 3.8

Speedometer jumps from zero to 40 ONLY when stopped and an electrical load is applied. (Climate control on/Headlights) Car went into limp mode once, shift into 1st to stop rough. Replaced input and output sensor, replaced battery, alternator fine. Car still shifting rough into 1st (downshift only) and speedometer still jumping.

I own 4 T&Cs. This is my favorite and oldest

 

did you ever figure this out mine is doin the same thing

 

Just a continued return..Have you's checked the wiring cables down below around auto box...got to keep mentioning this just in case.