I put all the wires for the pitot tube in wing just in case (with enough wire to reach cabin). (14 Ga) IIRC, one power wire supplies controller which in turn supplies the pitot tube itself.
In talking with Steinair folks during my panel build it turns out the harness has a power supply for pitot in one of the molex connectors but not a ground - so I'll run my ground wire to the grounding block but use the molex supply for my hot.
Since you have Dynon may be different (I'm using Garmin) but I'm sure if you give the guys at Steinair a call (Josh is the RV14 guru) they will give you the information you need.
