[BlueWing]

Ok, take the 478 Garmin that has XM. When you put it in a truck does the XM operate off a modulator inside the unit to play through your radio? Do you have to hard wire it into the radio? Or, do you have to buy a modulator and attach it to the Garmin unit?

 

[Jon]

There is no on-board FM modulator on the 478 - you'll need to connect the audio output jack to an off-board modulator (either wireless or wired to your truck's radio) if your truck radio has no AUX input available. (A cassette adapter is another option if you have a tape player).

 

[BlueWing]

Thanks for the quick answer Jon!!!

 

[DT]

The 478 comes with an external speaker built into the 12/24V adapter cable (http://shop.garmin.com/accessory.jsp?sku=010-10512-00).

While the sound is mono and fair at best, listening to the XM can be done using this cable...no other wiring is required.

 

[Toyo]

Go out and buy you set of the Bose Noise canceling headphones. I use them everyday in my van with my 376 and XM. Its awesome!