Fuse question

[Arfcollins]

Hi, can someone please tell me what fuse covers the map reading lights? As they are live when ignition is on I'm seeing if I can run a USB socket from there. Was OK with just the dash cam connected but when I plugged in the phone Bluetooth too the fuse blew. I'm hoping the combined current was too high just  because the Bluetooth battery was very flat, but I may need to think again.

[Arfcollins]

Hi, can someone please tell me what fuse covers the map reading lights? As they are live when ignition is on I'm seeing if I can run a USB socket from there. Was OK with just the dash cam connected but when I plugged in the phone Bluetooth too the fuse blew. I'm hoping the combined current was too high just  because the Bluetooth battery was very flat, but I may need to think again.

Now I'm puzzled. No fuse has blown. Only the map lights had stopped working, as had the double USB unit (2x 3.1A) but when I went back to it after tea and Google everything worked correctly again, but just for a short while after reconnecting the the USB unit. Then the same issue, the LED went out on the USB socket, and the map lights stopped working. I disconnected the USB again and the map lights came back after a few minutes. 

Is there a thermal cut out somewhere in the Blingo circuit ? I tested the USB unit on a spare battery and it works fine so it doesn't seem to be a fault in that. Am I right in assuming that 2 USB sockets at 5V and 3.1A will be drawing about 2.5A on the 12V circuit? 

Any advice appreciated!

[patch]

I think the berlingo senses a little bit more load on the light wiring so shuts it down. When installing simple towbar electrics, say for a number plate backboard for a bike rack, by tapping into the rear lights/indicators, you would want to install a bypass relay because of this behaviour. I'm using that logic as a possible explanation to what you are seeing.

[oilyrag]

Is it not possible to use a simple adaptor that plugs into the cigarette lighter socket, which has a heavier fuse?

[Arfcollins]

Is it not possible to use a simple adaptor that plugs into the cigarette lighter socket, which has a heavier fuse?

Please excuse the late reply Oilyrag. Yes, that's one way, but the idea was to dispense with trailing wires up to the top of the windscreen where I have the dash cam and phone Bluetooth. What I did in the end was access the leads to the lighter socket and attach wires to them using those connectors that cut through insulation without cutting the wire (not sure what they are called) . I removed some of the panels below the radio to give me a route  out for the new wires which are tightly taped together, which go across the inside of the glove box, then up the side of the dash. Because the taped wires are quite stiff they stay located inside the windscreen trim and enter the light binnacle at the top. This is quite easy to pop off. My USB socket is in there, and 2 USB leads pop out though an existing 'port' in the roof lining to power the two devices. It works very well. I've checked a couple of times that the USB socket is running cool and indeed it is. The new circuit shares the same fuse as the lighter socket so I'm not loading it any more than the previous arrangement. 

The new wires are only visible for a couple of inches. I probably could have hidden them completely but didn't want to do any more dismantling. 

I'll load some pics.

[Arfcollins]

      The only bit of exposed 12v cable.
      Cable exits the left side of glovebox into pillars trim.
      USB socket inside the light binnacle.
      USB cables exit.