How to Power a Nuvi 660 off of USB port (Run GPS, insead of PC Mode)


I borrowed two Garmin power supplies and tested the mini USB pinouts for conductivity between USB Mini Pins 4 & 5.

I Tested the following supplies and they boot the Nuvi 660 into GPS Mode instead of PC Mode:

Garmin AC Supply 362-000283-3 Boots 660 to GPS Mode. 2.0A
Pin4-5 Shorted.

Garmin DC Supply GTM-36 Boots 660 to GPS Mode. 2.1A
Pin 4-5 Shorted..

Garmin DC Supply TA20 Boots 660 to GPS Mode. 2.0A
Pin 4-5 Shorted

Unknown Techniques Supply Boots 660 to PC Mode. 2.1A
Pin 4-5 OPEN

Garmin DC USB Charger UB40F0 (With USB 4 pin to USB Mini 5 pin cable) 2.1A
Boots 660 to PC Mode. Pin 4-5 OPEN

So, based on these findings.... I took an USB To Mini USB cable, and CAREFULLY Soldered a short between USB Mini Pin 4 & 5... It's painful, but can be done...
And Plugged this modified USB Cable into the Garmin DC USB Charger UB40F0 (That just failed to boot to GPS Mode).....

Obviously I labeled this cable: "DC POWER OF GARMIN ONLY, NOT FOR PC MODE!!!"

AND THE 660 is BACK AMONG THE LIVING!!! Powered off USB port!! Shows it's charging, does everything it should, with a scrambled directory, and a failed rear connector, but obviously it does not know this, and so it keeps on going!!!

So if you need to power off the USB, you know what worked for me!!!

Lifetime traffic is dead, but Lifetime maps On external SD Card will keep this old dog going!!!

A 2689LMT in both our cars that we love... and a Nuvi 660 with Lifetime Maps that we have had literally forever.... And a 2011 Ford Escape with Nav System that is totally ignored!


Good for you!
good info.


Way back when I used my 350 and 660 I found this procedure worked for using the Nuvi in GPS mode while attached to the computer:

With unit off, plug into USB as usual, let it appear on the computer as a drive.

At that point, unplug the USB from the unit, wait for the "maps loading" message to appear, and at that point plug the USB cable back into the unit. The unit will continue to load into GPS mode and run off USB power.

Nuvi 350, 760, 1695LM, 3790LMT, 2460LMT, 3597LMTHD, DriveLuxe 50LMTHD, DriveSmart 61, Garmin Backup Camera 40 and TomTom XXL540s.

I stumbled upon a 'multiple

I stumbled upon a 'multiple power connection' approach, but I didn't document the procedure as accurately as you did.

But I wanted something more user (and connector) friendly...

The current temporary 'fixed' cable will be replaced by a short USB Mini 5 pin extension, a USB Mini breakout board with pins 4 & 5 jumpered, and regular USB cable +5V power to Pin1 & Ground to pin 5 on breakout.

All that to make the Garmin DC Supply work (Which must be only for battery charging, though it has plenty of current for running the 660 in GPS Mode and sold to me as such!)

A 2689LMT in both our cars that we love... and a Nuvi 660 with Lifetime Maps that we have had literally forever.... And a 2011 Ford Escape with Nav System that is totally ignored!


Very nice!

Bob: My toys: Nüvi 1390T, Droid X2, Nook Color (rooted), Motorola Xoom, Kindle 2, a Yo-Yo and a Slinky. Gotta have toys.

How to boot out of PC mode with a USB power cable only

My supplied power cable/traffic receiver's plug wires broke, and I couldn't fix it. So, I messed around looking for some sort of undocumented 'easter egg' solution. It turns out there was one.

Here's what works for me 100% of the time with my Garmin Nuvi 1490LMT. Although I don't have traffic using this method, I can use a regular USB cable plugged into my car's USB power port to power the GPS up to load the maps and use the navigation functions;

1) Connect the USB cable to the GPS and vehicle's USB power port.
2) Power up the GPS until the PC mode is reached.
3) Press and hold in the upper right hand corner of the GPS screen for 15 seconds or so, then release.

The GPS will reboot into maps/GPS mode.

It's a good workaround if you need GPS and maps, and only have a standard USB cable.



Yep, that method is in the

Yep, that method is in the FAQ, already.

Frank DriveSmart55 37.322760, -79.511267

Couldn't find FAQ to force boot to Navigation mode

phranc wrote:

Yep, that method is in the FAQ, already.

Hi phranc,

I must be missing something. The only place I found the steps I outlined were in a FAQ to boot into MTP mode and connect to an XP PC. It was in the Garmin device FAQ, titled "MTP Mode Garmin| How to change it to Mass Storage." ( see ). Note that my 1490LMT booted all the way to navigation, not a developer screen, so steps 3-7 did not apply in my answer.

I searched the "Index to FAQs", "all FAQs" list and "Garmin NAV" FAQ using various search words like 'Boot' 'USB' 'power', cable' etc. and didn't see any place telling how to bypass the PC mode to use navigation and maps when using a standard USB cable in a car with USB power ports.

If you have a link to the FAQ you reference, I'd appreciate it. I really tried to find it.


Ok, I couldn't find a FAQ to

Ok, I couldn't find a FAQ to back me up, but searching on this "" brings up numerous references to this method for booting to Navigate mode when connected to a power source with a USB cord that goes back several years.

So, it should be a FAQ. If you submit it to jgermann, perhaps he will make an entry to the FAQ for this.

Frank DriveSmart55 37.322760, -79.511267

An easier way than soldering or unplugging

An easier way is to use a USB data blocker (otherwise known as a USB condom). I bought two of them to use when I charge devices on hotel room, airport, coffee shot and other insecure or untrusted public USB charging ports that may be hacked and contain data scraping tools or malware injectors.

The device may try to boot as a storage device, but when no data connection is sensed, should connect as if connected to power only.

See for an example.


if the wires are color coded as most connectors are molded to prevent opening. I am assuming you modified the larger USB end.

I've (for other reasons) cut

I've (for other reasons) cut apart multiple USB cables... The Color coding of the wires does not always follow same exact colors... but often they are Close.... You can also find color code USB pictures...With Pinouts....on line..

At the time of the experiment, I had found a post elsewhere where someone tucked tin foil in the connector to short two pins together..... I did not see that as a viable solution... but pointed me in the direction of the final fix...
I had spare cables.... Some would act as power up cable, and some would only work as data cable. Cut one of each USB apart in the middle, and found one that powered GPS had 5 wires, data only 4..

Between the USB Breakout connector I had so as to ohm out the wires, and on line sites that provided accurate pinout and pretty close color code info, I was able to determine for certain which 2 wires to solder together for + Voltage, connected the grounds together, and didn't connect data wires at all... All that is in the FAQ..

I ended up with 1 cable spliced in middle protected by heat shrink tubing, and 2 cut off ends that were tossed...

Over the ensuing years I have used this cable on multiple GPS's as a power source only.... Works like a champ!!!

That Tired old 660 STILL WORKS... and has Current SE USA Maps on it.... that resides on an SD memory card!

A 2689LMT in both our cars that we love... and a Nuvi 660 with Lifetime Maps that we have had literally forever.... And a 2011 Ford Escape with Nav System that is totally ignored!


I still have my 660 that I purchased brand new and I still get Traffic but know map updates.