2007 Dodge Caravan Instrument Cluster

Electrical problem
2007 Dodge Caravan 6 cyl Front Wheel Drive Automatic 50k miles

The left lower portion of my speedometer lighting is dim, almost like there are some failed light bulbs in that area. However, after driving for a while, the lights came back on to full strength. This just started happening and occurs now all the time.

My questions are:
Could this be related to a turn signal that had blinked and clicked very rapidly just a week before--this has not happened since (usually a rapidly blinking turn signal indicates a failed turn signal)?
Is this a failing bulb(s),
Could the voltage regulator be failing/faulty?
Could this be due to a battery that had died previously and was jumped (the car's original battery, probably needs to be replaced)

Thanks,
Kurt Young