low voltage

my battery gauge keeps dropping into the red there is minor light dimming but not much.hooked my voltage meter up and it says 14.08 volts and had my alternator tested and my battery and they both tested ok.any ideas.kinda worrys me when i turn the a/c on it dropps real far on the cars gauge especially when breaking.its a 95 se.can any 1 help?

Check the connections to your battery and the battery leads for corrosion. If they are good check the wire at the alternator to make sure that it is not dirty, happens some times and will result in low voltage to the battery and the rest of the car. Finally check the ground wires and make sure that they tight.

thank you gtp i needed a new battery + cable.it went away as soon as i replaced it.my car just aint been the same since the garadge put it back together