Chrysler Repair: Problems with Speedometer/no shifting, 1999 chrysler concorde, chrysler concorde

Question
I have a 1999 Chrysler Concorde the speedometer is stuck at 0. Then when I am driving and picking up speed the gas gauge goes up and when I slow down it goes down. Then it sounds when I am driving it, it sounds like it is stuck in one gear? How do I fix this? How much you think it would cost for me to take it in and have someone fix it?

Answer
Get a free fault code readout at an Autozone parts store or similar nationwide parts store. That is done with a code reader that is plugged into a socket under the dash. Ask for the 4-digit fault code(s) then let me know what it is. I suspect your output speed sensor on the transmission has failed but let us verify that rather than assume. It costs a little under $100 and can be installed in less than half an hour, simple unscrew the old, screw in the new after lifting the tab on the wiring cap and removing the connection. It is located on the driver side of the transmission the far end of it.
If it has indeed failed, that would explain also why the transmission won't shift because the trans needs to know the reading from that sensor to shift properly. The fault code for that sensor is 0720.
Lets deal with the fuel gauge as a separate issue later.
Roland