voltage issue

[user_deleted]

so i did all the steps that lunaticfringe outlined above EXCEPT: fully charging battery and having it load tested.
i purchased a new voltage regulator and installed it, but the problem still exists-but much less frequent.
i did a trip a couple of days ago, about 500 miles and this i what i've learned:
when the voltage drops and the yellow check engine light comes on, if i back the throttle off to "0" (no throttle) the voltage immediately climbs back to the 14.2 and the check engine light goes off.
so apparently, this is an on-throttle condition that can be remedied by completely closing the throttle application.
any ideas of what could be causing this?

are you saying that on a 500 mile trip all was fine? battery stayed charged? volt meter readings consistently good? and now at steady speed cruising you start to lose charge but when you allow the motor to drop down towards idle....NOT specifically idling....but decelerating towards idle....the volt reading goes back up and stays there? are these the correct symptoms i'm describing? if so you've just described loss of current flow. contrary to popular thinking and ancient myths....a negative ground system has the current flowing from positive source to ground....NOT the other way around. your symptoms if i described them reasonably accurately are classic "ground fault" symptoms. before you do anything else carefully go thru all your grounds by removing, checking, cleaning, cleaning ground platform, reattaching. they are as follows: your 4-wire cluster at steering neck/lower steering triple clamp.....large braided dog-bone under rear of airbox base plate, 2-wire ground cluster at battery box area....negative battery cable to frame point.
lastly....and it costs 10 cents....remove fusebox lid...view schematic...find battery fuse...replace same. common auto style mini-blade fuse.