What is going on with the guages not working sometimes...starts usually with RPM on 1992 Pontiac Grand Am

Most of the time the guages work; however, periodically, the RPM will stop working. Sometimes the speedometer won't work. Sometimes the battery needle will pulsate and the engine will pulsate with it. Maybe these are two seperate issues, but not sure.

Asked by for the 1992 Pontiac Grand Am