Hello I have an 02 town and country 3.8 motor the other day the speedometer started jumping then the transmission started acting up. I did some research and found that the usual problem is the speed sensor. so I changed both speed sensors. now the transmission is acting fine but the speedometer is still jumpin when in gear and not moving..if you give it gas and start to move the jumping stops. but if you stop at a red light it starts back what else could it be... I have already recalibrated the instrument cluster too thankyou how any hintson other things to check!

 

Sound hellafa like you have an earthing cable there as when you are moving vibs and airflow raise cable from body/trans. A just incase senario...

 

can you explain that a little more plz

 

I agree sound like you have a ground issue. I had something very similar happening with my 98. However, what worked for me was to put a new ground lead from the engine to the battery!

 

Yeh check all the cables around your auto box and exhaust pipe area for grounding.

 

auto box?

 

have one with nearly same problem "not solved yet" . But it's only the speedo. Not any problems with the transmission. Looking forw. to hear out come !