5 pin mini-USB plug connector
Pinout compatibility: Garmin Montana 600Garmin Montana 650Garmin Montana 650tGarmin Nuvi 1240Garmin Nuvi 1245Garmin Nuvi 1340LTGarmin Nuvi 1340T CEGarmin Nuvi 1350TGarmin Nuvi 1370TproGarmin Nuvi 1390T proGarmin Nuvi 1450TGarmin Nuvi 1490lmtGarmin Nuvi 1490TGarmin Nuvi 1490tproGarmin Nuvi 1490tvGarmin Nuvi 1690 nuLinkGarmin Nuvi 200Garmin Nuvi 200wGarmin Nuvi 205TGarmin Nuvi 2360LTGarmin Nuvi 2495LMTGarmin Nuvi 250wGarmin Nuvi 255TGarmin Nuvi 255WTGarmin Nuvi 2595lmtGarmin Nuvi 265TGarmin Nuvi 265WTGarmin Nuvi 350TGarmin Nuvi 360TGarmin Nuvi 500Garmin Nuvi 5000Garmin Nuvi 550 AllroundGarmin Nuvi 550 AllroundGarmin Nuvi 750TFMGarmin Nuvi 760TFMGarmin Nuvi 765T proGarmin Nuvi 765TFMGarmin Nuvi 770TFMGarmin Nuvi 775TFMGarmin Nuvi 860TFMGarmin Nuvi 865T proGarmin Zumo 400
|1||+5V||5 volts DC|
|2||data||not connected / float|
|3||data||not connected / float|
|X||GND||connected to pin 4 (GND) with 17.3K ohm resistor|
Standard 5 pin mini-USB connector has pin X connect to ground (pin 4)
through a 200K ohm resistor (Note: The normal USB connector has only 4
pins, the mini-USB has 5 pins). To place Nuvi into charging mode, the
200K ohm resistor must be changed to 17.3K ohm. (also successful with
22K ohm resistor from Radio Shack, also a cheap 1/8W, 5%, 15k ohm
resistor will work just fine!)
Nuvi behavior depends on mini-USB plug connection. (IMHO) it is like this:
pin X not connected – data cable, nuvi connects to PC as removable drive, navigation NOT possible.
pin X & 4 short-circuited – USB supply 500mA, possible navigation,
pin X & 4 connected through 18kOhm resistor – Garmin supply 1A, possible navigation.
pin X & 4 connected through 22kOhm resistor – Garmin supply 500mA, possible navigation.
I personally modified a cable that connected pin X to pin 4 (shorted), and verified the 500 mA charge behavior as noted above.
I simply waded up some aluminum foil and stuck it in the connector so that pins x and 4 were shorted. Works.
Nuvi requires 1000mA for simultaneous charging + GPS operation [many ‘generic’ 12VDC-to-USB adapters output a maximum 500mA]
Garmin Oregon requires a resistor of at least 47K ohm for running in
external power supply mode (100K ohm also works). Smaller values are
working, too, but Oregon then first shows a message that an unsupported
accessory was found.
pin X not connected – data cable, GPSMAP 62 connects to PC as removable drive.
If it fails because it is connected to your car battery, it switches to external power supply mode after several secondes.
pin X & 4 connected through 47 k Ohm resistor – GPSMAP 62 switches
to external power supply mode immediately without waiting.