TomTom sat nav

[Groutmaster]

So I thought I had found the right plug to connect an additional sat nav to (under tank cover on left) it reads 12v with ignition on but won?t power the sat nav.
Am thinking there?s a canbus that doesn?t like it.

Any ideas?

 

[Groutmaster]

Resolved!
I had connected + & - the wrong way round.
For reference:
1 = negative
2 = 5volts
3 = 12v live

So what I had previously read up on here stating 1 & 3 the opposite way round is incorrect