Thread: Using TMC in Garmin nuvi for free

Originally Posted by Superduper67

You would need to drive in a different area. They are not "stuck", this is how they are supposed to work. FM tables are filled automatically with the radio stations carring the traffic signals in the area arround you.

The "1527,0,0,0" didn't do anything for my 765 or 855.
I have inputed the codes with units on desk. On 1390 with GTM25 (USB) that is not possible since it doesn't get "back" the power from the USB port.

I understand driving to a different area will change the frequencies, but when I do the test from my desk I am not connected to a satellite, therefore It is not searching for FM frequencies. By hitting reset it should clear the FM frequencies, then do a new search when I am connected to satellites in the car.

Your 1390 differs from the 765T, you only have one power connector, that is the USB connector, THIS WILL NOT POWER YOUR GTM25.
The 765T has a power connector on it’s mount, this is where the GTM20 commects. There is an additional USB port, the USB port is where the home charger plugs in this is senfs power to the GTM20. This is how I’m able to work from my desk. It performs all functions as if I’m connected to the cars power supply, only difference is no satellite signals.