The best way to connect a sat nav on the Ten is by using the spare connector behind the panel under the dash. If you remove the panel you will see this small unused black 2-pin connector sitting under the tacho. It is wired into the sidelight circuit so will become live when the ignition is on (and also when the key is in the "P" position). It's also handy as the other pin is an earth so you don't need to faff about running ground wires. The sidelight circuit is fused at 10A, so when running a satnav a more appropriate 3.5A fuse would be a good idea, so as if the sat nav (or mounting cradle fails) it will blow that fuse and not the sidelight's.

The only snag is the male part of the connector is almost impossible to get hold of, so you will have to cut off the original connector and replace with something more common (as in the picture).

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