Voltage on headlight high. 14 volts +

Probably normal. Just means the system is charging the 12 v battery. Check the voltage at the jump spot in the fuse box and again using the display diagnostic modes. Let the system remain in Ready for 10 minutes and it may go down. Plus some digital meters have been known to read a little high, like the free ones from Harbor Freight.

Prius v Display Audio Service Menu w Battery Check | PriusChat

 

Was that value measured at the bulb connector with both lights operating, with good bulbs? If not, it doesn't mean much; some voltage drop between fuse box and bulb is normal with operating bulbs.

After frequent complaints of short headlight bulb life in some early 3rd-generation regular Prii, Toyota issued a technical service bulletin to correct the problem by splicing in an added wiring harness on each side. It amounts to adding a small resistance in series with each bulb. I haven't heard of the vagon being involved.

 

Normal when in Ready Mode, our car measures 14.4v at the jump terminal in the engine fusebox. I suspect that that's the reason why the Prius headlights burn out pretty quickly. The plus is that the bulbs burn a bit brighter.

 

My 2012 Prius v is 14.3 or 14.4 volts when in Ready. 14.6 seems a little high, but not much.

16:50 minutes to 18:05 minutes describes the 12 volt charging system.

 

You can see 14.6 when the 12v battery has been discharged a little. The regulator will back off incrementally as the battery charge comes higher to perhaps 13.6v.

 

You haven't said whether you tested the voltage at the bulb connectors with the bulbs in place and lit. As CR94 pointed out, that's the only measurement that tells what you need to know. You need thin backprobes for your meter in order to do that. Insert the backprobes around the outside circumference of the rubber wire seals.

What you need to know is the voltage after the expected voltage drop caused by the wire harness, and without the bulb present drawing current, there is no drop.

-Chap