Read post #10 here: Rand McNally question
RandMcSam is a Rand McNally representative here on irv2.com, and is happy to help with questions.
It's not clear from your post, but it sounds like your GPS is connected to your entertainment center in some fashion. That may be specific to your mfgr.
2000 Winnebago Ultimate Freedom USQ40JD
, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"