2000 'burb' electrical gremlins

This is an update to a previous thread. My 2000 suburban has intermittent electrical issues. The speedo and rpm will occasionally go dead. The transmission will sometimes feel as if it is trying to start in a higher gear(no power on start-off) and just recently pulling a trailer, the shifter lights and radio lights would flash with the turn signals. Later with the headlights on, there was not enough juice to even flash the turn signals. The gauge read 14volts, but could it still be the alternator? Should I check any specific connections or do I just need to get started checking them all? Any suggestions would be greatly appreciated.

Check all connectors under the dash.