xp8103

Ok, I own a 4th gen but my guess is that the system in the 4th gen is the same as the 3rd so I'm here to widen my net cast.

I haul a slide in truck camper. With the sat radio antenna placement on the passenger side rear of the cab roof, my cabover obliterates sat radio reception. Interestingly, I didn't lose nav. So I assume that the nav gets its signal from some other place. So I buy myself a Sirius/XM magnetic remote antenna ($10 from amazon.com), stick it to my hood, forward of the base of the windshield about 8 inches and run the wire inside, to the passenger side kick panel. Remove the panel and there is a white connector and a yellow one. Trial and error showed the yellow one as the culprit. I unplug the yellow connector and put my remote antenna and presto, sat radio. Figure I'll test it over the 4th weekend. A heavy cover of foliage will make it skip a bit but otherwise it worked just fine with the camper on. Yeah, except that now, nav doesn't work. Get "Locating satellites". Even after I removed the camper. I unhook the remote antenna and plug the OE antenna back in and presto, again.

So. So? If the nav gets it signal from the same antenna why would it work with the camper on when the radio doesn't? And apparently not all sat antennas are the same, assuming that the nav and XM share the antenna on the OE unit but a remote XM antenna is only that?

Super Dave

A good nav antenna will operate under a cover, but it won't "see" as many satelites, and therefore will reduce the accuracy a bit. This is because there are 10-12 satelites in the sky your nav can use at any given time, but only one Sirius satelite. When its view is blocked, you're hosed.