I wound up with two Lowrance 522 heads, and decided to use one for sonar connected to a transducer, and one for gps (internal gps). The gps unit will not have a transducer, since it would interfere with the other transducer. These units will not support networking for the internal gps.
Finally, to my question: I can't get the unit without the transducer to initialize. Does it require a transducer to be connected?
Dern, I swapped it the other way. I took the non-responding unit and connected it to the power and transducer and it worked. I ran out of time, and didn't try to see if the other unit would initialize without the transducer. I'll try that later this week when I get back down to the lake.
Chris, I'm running this off of the internal GPS antennae on this model.