My RPM gauge just randomly started bounceing a couple days ago. Im not sure why this started. Could any one give me some advice?

 

is your engine running rough?

 

no it runs fine, i just got a tune up last week. It started happening after i installed a sound system

 

I suspect your sound system is drawing more juice than the alternator can provide and the voltage is dropping. This will make the instruments, especially the tach, act weird. Diconnect your system & see if the trouble goes away. If it goes away, then you need a bigger alternator.