Recently I've noticed that while I'm driving, my battery voltage is jumping. Sometimes it is around 14 volts and sometimes around 11 volts. It is happening in the same conditions ( I am not turning anything on or off). Is this a sign of dying alternator???

 

sounds possible, dont think it could be something else

 

Bad ground? If you got some free time do the DIY ground kit, if it works your welcome. If not, buy an alternator.

 

Ground is good. I did it not long time ago. So it has to be an alternator.

 

clean your battery connections and see if that helps. does anything dim when the voltage jumps around?

 

Nothing dim. But don't bother anymore. It died. Voltage is constantly around 11V and it failed an alternator check on my battery charger.