Wiring gtm 25 tmc usb connector

Hi,

I like to put a new mini usb connector on the TMC / charger cable since the old one came of. I know that I need a 5 pole mini usb connector, put 1 on 5volts, 4 and 5 on ground. But I dont know which way around to put the green and white data wires on contacts 2 and 3 on the mini usb plug. On the TMC receiver there are 7 pads:

1 ground black

2 n/c

3 data green

4 data white

5 n/c

6 n/c

7 +5volts.

Can anybody check with a continuitytester where green and white go ?

Does anybody know the correct wiring ?

Please help. A new cable with tmc costs almost as much as a new gps.

Thanks, Manfred , Berlin

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I have the same problem. However, there is no black wire but a yellow wire with light green dashes. Is that the same as the black wire>

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There are several versions of the TMC receiver. The one I had was a GTM 25. In the cable from the receiver to the Nüvi mini USB plug there should be 4 wires.

plugpin1 red +5V

plugpin 2data white

plugpin 3 data green

plugpin 4 has no wire

plugpin 5 black ground

you could check with an voltmeter to find the ground wire for the 5 volts (check against red) or with an ohmmeter, since the ground wire is routed through to the cars lighter plug. I dont know if the little current an ohmmeter uses can damage anything.

If you found and connected the red wire and the ground wire the Nuvi should be powered, probably showing a USB connection symbol when pin 4 is not connected.

dont forget to install the 27 k resistor in the plug from shield to pin4 to tell Nuvi that a receiver is connected.

Manfred

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Since nobody knew, I borrowed a coworkers satnav, took the receiver apart and checked with a ohmmeter. Contact 4 on the mini USB plug is NOT connected to ground as I had read somewhere on the net.

receiver-----------------mini USB plug on garmin Nuvi

1 ground black--------------- contact 5

2 n/c

3 data green------------------contact 3

4 data white------------------contact 2

5 n/c

6 n/c

7 +5volts red---------------contact 1

inside plug:

contact 4--R27 Kiloohms--plugs enclosure

The trick is to connect the metal shild part of the mini USB plug with the plugs contact 4 via a resistor 27 Kohm. When contact 4 is connected to ground, Nuvi expects a charger. When contact 4 is not connected at all, Nuvi expects a data connection. And when contact 4 is connected to the metal shield part of the plug via a 27 Kohms resistor, Nuvi expects the TMC receiver. If the receiver is recognized, the setting appears in the menu and the green button appears in the map.

Manfred, Berlin

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Garmin Nuvi 265WT.all functions, navi/charging/etc work perfectly...except traffic. The green traffic logo on GPS display screen no longer appears. I replaced the cable (original one had a damaged USB plug end) & same-no traffic logo. I put a new end on the original cable-same result. So, I placed a 27K R. between pin 4 & the braid of the cable.(the braid had no resistance to the USB plug shield when I previously checked with meter, so installing a 27K R. is equivalent to "between pin 4 and plug shield"no?) Your "Terminology" My understanding is..the plug shield=the metal part of the USB cable. The jack=the port of the GPS device. Cable has circuit boards in the antenna & DC plug & I wonder if that is part of your description & info above? Is the 27K R actually inside the USB plug end or on the circuit boards? Not sure if there's a physical difference & maybe the reason why green traffic symbol still doesn't illuminate on GPS display. Please help, if you see where the issue may be.

Tks

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