I am having a electrical issue while running and was wondering if it could be a floating ground or possibly something else.

The volt meter drops to 12volts on the instrument cluster when turn signals or anything else electrical is turned on and even lower when the brake pedal is pushed and the needle cycles back and forth

Any help would be greatly appreciated!

84 first generation with 12a

 

Make sure all electrical connections are clean and tight, battery cable grounds and positive cable, second is to actually test with a multimeter, the voltage will drop some with a load on the system.

 

Have the alternator/battery checked.