Alternator...?

[Kneedrager]

Ok... So my '04 4.4 has just started with the famed electrical gremlins. Active suspension, turn signals, radio all coming and going with a mind of their own. After doing some research I opted to first do a battery re-boot. No help. I then replaced the battery and actually got 20 - 30 care and error free miles before the radio became possessed again. WTF...

I checked the voltage at the battery without the car running and it was at 13.5 - 14 volts. i then started the car and it dropped to around 11.5 volts.

Is my next step a replacement alternator? As always any help will be greatly appreciated. -Scott-