Amp gauge showing around 20 amps whole time I was driving.

1..YUP. Make model year and is it stock
2...Run over to MyMopar.com and download the closest you can get to a service manual. You may have to settle for Dodge vs Plymouth, etc
3...Take your meter and check battery voltage when warmed up and running at fast idle to simulate low to med. cruise RPM
4...You have any other mysterious electrical failures, such as lamps or radio?