> Having communication problems between the T2 and a Nuvi 350. Sporadically I > get "Serial Accessory Requires External Power" and then I lose my call sign > on the nuvi display.
> Also I have checked the voltage from the Garmin power point and it is > a constant 5.172 v I was seeing a problem like this for a while. It turned out it was the power supply cable I was using with the Nuvi (into the back of the cradle, of course). When I would measure the voltage at home, it was always a steady 5v, but as soon as I started driving around I would get "Seiral Accessory Requires External Power". I had a bad crimp on my home-made power cable, and the vibrations of driving around would instigate the problem. I built a new cable and my power problems are gone. Maybe try a different power cable for the Nuvi? And, check that the connection to the cradle is good. Mine tends to wiggle out--Mini-USB isn't a very sturdy connection. Tom KD7LXL
