Turn signals and radio??

My turn signals and radio work sometimes and other times don't.  Also the voltmeter starts out hovering at around 13 but if I start to run about 60 it goes up to 15 or so.  Anyway I was wondering after reading one of the other post if maybe a bad lead into fuse link box could be causing both of these problems.
FYI I just finished a complete overhaul on the interior and took out a bunch of bubba wiring that had been installed for one of the those old phones that used to be mounted in the cars, with a rather large silver box that had to be installed next to the jack.  I was hoping that was the problem with the voltmeter but does not seem to be.
I have had the wiring and alternator checked at an Advance Auto and both are checking out fine.
The fuse link could be an easy answer bur I'm not holding my breadth considering its an electrical thing which is all voodoo.
Thanks for any suggestions / thoughts.

I wouldn't put too much stock in the volt-meter readings...they ain't all that accurate to start with. As long as it moves to the "+" side, and not the "-" side , it's working!

The radio & t-sig problem may well be in the ignition switch.
Do they both stop working at the same time?
Do they stop working at random, or consistently when you turn, hit a bump, etc.?

agree with joel about accuracy of meters. also when it is charging most times it will be regulated up to 14.5 volts before it is considered over charging. if it goes up too high regulator may be bad.