Power Garmin Nuvi with generic USB cable

[markopolo]

The power cable that comes with your Garmin GPS powers the unit in GPS mode when plugged into the 12v outlet in your vehicle. If you use a mini-USB cable attached to your computer your Garmin will go into Mass Storage Device mode so that you can upgrade or add files etc. If you use a generic automotive mini-USB power cord your Garmin will go into Mass Storage Device mode.

The Garmin power USB pinout is designed that way.

On the web, I learned that you can trick your Garmin into going into GPS mode when using a generic mini-USB cable or generic power supply. This is useful for me because I have a generic device power supply / holder that I can for our phones and now my Garmin. It cost about $10 and I had to cut a little notch on the holder to be able to plug in the Garmin GPS. This means less cable and stuff in the vehicle.



The trick is to plug in the generic mini-USB cable or power cord and plug it into the Garmin. Your Garmin will go into Mass Storage Device mode and there will be a picture of a computer on the Garmin screen. Unplug the cable on the back of the Garmin and plug it back in as soon as the picture of the computer on the screen disappears. You have to be quick. It works every time for me.

I think this trick will work with all Garmin GPS but I have only tried it on two Nuvi 250's.

My Garmin came with a windshield or dash mount holder. Some jurisdictions ban devices such as GPS's that are in the "visual range" or "obscure" the drivers view. I think that California now allows the device to be mounted in the lower right corner of the windshield (previously it was banned altogether). Hopefully, this direct 12v outlet mount keeps me in compliance.

[Mike]

I'm always tinkering with POI files and do an occasional disk defrag on mine
so I like being able to switch back and forth between MM mode and GPS Mode.
I would normally just plug my nuvi in using the mini-USB to USb cable that came
with it when I want to fiddle with the files on the unit.

When I want to switch to GPS mode,
I eject or safely remove hardware with the netbook, if the nuvi is plugged in.
Unplug it and let it power off.
Put my netbook into low power "Standby", ("Start", "Turn Off Computer", "Standby")
I let it go into Standby mode. The OS is "asleep" now, so it doesn't see new devices
get plugged into the USB ports, but I think the USB ports still have power.
Plug the nuvi into a USB port.
Wait. The nuvi will boot up into MM Mode, but if I wait a bit longer, I think it gets
tired of waiting for a handshake from the OS/laptop, and it will reboot into GPS mode.
Then once it's in GPS mode I press the power button on the netbook, and wake it up.
I now have GPS mode and can use my laptop to charge the nuvi, while adding addresses
or whatever I want to do in GPS mode.
Works for me.
I think your idea works as well, probably for the same reasons. There might be a
danger in just pulling the power out of the nuvi, while it's visible to your computer.
You might corrupt the files/file system on it by unplugging it, before issuing an eject.
Something to consider. I've screwed up flash drives for the same reason.
I have one of those universal vent mounts but use it solely for my flip phone.
I bought one of those dashboard sandbag things for the nuvi, but we sit it on top
of the ashtray below visual, and so far it seems to work pretty well there.

[markopolo]

You could be right Mike.

I think I'll use it with power supplies instead of the computer when doing this. My phone charger also works with my Garmin.