With the Roadtech 660 can you listen to the fm and the other audios without plugging into the aux port ,and do you still need the interface.And what does wire in the aux line mean? I think I am confusing my self,I think the term Electronically Challenged applies here.
Hope this clarifies and hopefully this isn't too long.
The Roadtech 660 has a few different sources of audio output - Navigational Prompts, MP3 playback, and Audiobook playback. The 665 adds XM Radio.
In order to hear anything from the GPS, you have to route the audio out from the GPS with a cable, to the AUX input of your radio - e.g. wire in the aux line. Then you must select AUX as your audio source on the radio.
In this mode, you can not listen to FM, AM, CD, etc. and still hear the navigational prompts. But at least while here, they gave you the ability to listen to MP3s, audiobooks, or XM (665) while using the GPS to get around.
Of course, you don't have to ever listen to the GPS navigational prompts and can continue to listen to your choice of audio (FM, CD, etc.).
Now enter in the Navigation Interface Module. With this accessory installed, the rules change a bit.
The audio out of the GPS is routed to the NIM so that the NIM can listen to the GPS audio stream for two purposes. One is to listen for a signal from the RoadTech only version of the GPS. This is how it knows the GPS is about to speak (Turn Left, etc.). When it hears the signal, it will interupt whatever audio source is on the radio much like the CB does. Doesn't matter if your on FM, CD, or weather band.
Then the NIM will route whatever audio it continues to hear from the GPS to your HK radio and then release the radio back to the original audio source when it hears a termination signal from the GPS - not 100% confirmed on the term signal. Since the NIM has interrupted whatever mode you were in (FM, CD, etc) you will hear the Nav prompt and this is really cool. This audio interruption is a mono source, and uses the bluetooth phone channel of the KH Radio (for those who like extra details).
Now let's throw in the CVO factory wiring aspect into the mix.
The factory setup of the CVOs in question, is to wire the GPS audio only to the NIM. This allows you to listen to your favorite audio source and hear NAV prompts. However, it poses one specific challenge.
You have no way to listen to the other audio sources of the GPS (MP3, Audibook, or XM in the case of the 665). In order to listen to those audio sources on the GPS, you have to open up the fairing and split the GPS audio out with a y-cable and run one line to the NIM and one to the AUX input of your radio.
Now you have a few choices. You can select your audio source of choice. Should it be the audio sources on the GPS, you would just select AUX over any of the other available choices.
Now, here's the fun part. If your on AUX and you are listening to say MP3s, and the GPS has a Nav prompt to boast, the following happens. The NIM will interrupt the AUX channel to get the NAV prompt to the radio. Doesn't matter that you were already listening to the GPS via the AUX line. It essentially will interrupt itself. No big deal really, but it is a source of one bug. I won't go into that here unless someone asks.
Let me know if this put everything into perspective, or if you have additional questions.
- Jeff