ben g said:
How does that work, strictly in newb terms? You obviously plug that into the fuse box, but how do you then wire the dashcam into that gadget?
The dashcam will have an external power supply (12V to 5V converter) so it depends how that power supply is terminated. Some are the type that you plug into the fag lighter, in which case you could either just cut the fag lighter plug off to give you two bare wires. The positive goes to the wire on the piggyback fuse thing, the negative goes to any chassis ground point (there is a crosshead screw just below the fusebox which is very convenient).
Alternatively, you could junk that and just buy something like this...https://www.amazon.co.uk/Graceme-Charger-Inverter-Converter-Connector/dp/B075K8H4DV/ref=sr_1_3?s=electronics&ie=UTF8&qid=1529582558&sr=1-3&keywords=12v+to+5v+dc+converter+dashcam
You need to make sure it has the right output connector to plug into your dashcam of course, most are micro usb nowadays but check.