NOOB wiring question

[pootler]

Hi - new to the forums.

I have been building a car pc for the best part of two years on and off :-)

I know car pc's have dropped off the radar- but its what I have to work with.

This is not professional, and I am using the bare minimum hardware that I have , and that I can get?

It consists of a Windows 10 Tablet which is  placed in front of the main fascia.

It is not in the fascia  and I have done no fancy work to make it fit in - it looks fine.

I have a box that fools my honda into thinking that the audio output of the tablet is  part of the multi cd player, so  it ouputs fine.

All of the accessories are usb and housed in a separate box in the glove compartment.

There are five usb devices , in a powered usb 3 hub. 

The tablet has a full size usb port.

This enables me to receive DAB radio, external GPS, Bluetooth receiver, windows mce remote. and external usb microphone.

Although I have a shiny windows tablet in front of me, I have NO intention of touching it whilst driving - the system is set up so I can input 95% of info using  a cheap chinese steering wheel remote  ( MCE ), for  switching functions, and I also have limited voice control.

Not forgetting hands free.

The hub receives power from a 12v to 5v convertor ( 5V 3A ) via the acc cigarette lighter fuse

The tablet receives power direct from fusebox  ( 12V 3A) via the acc fuse.

This is done with add -a -fuses, so additional fuses are there for the devices.

Both provide power when ignition is off for listening.

o.k, so everything works, but I have one major frustration - you may all laugh now :-)

The install works fine when in 'acc'' mode, so I can listen without the car running.

But , when I turn the engine on,  the Honda  FR_V disconnects all power to everything :-(,  so the tablet survives ( it switches to battery power for the brief moment it loses it from the car), but my accessories disconnect , and with the wonder of Windows ( ! ), they dont' connect properly after that.

The unit needs to be restarted to begin working correctly again ;-(.

Now , as explained , when it comes to electrical stuff, I am  total NOOB, but can follow clear instructions.

Does anybody have a solution that I may be able to follow to prevent this?

I  cannot have any permanent feed to the usb accessories, as this would drain the battery fairly  quickly ( the hub is drawing around 2A )

Many Thanks in advance 

[Trevor]

Hi....welcome to the Forum

The 12volt system is designed to avoid battery drainage and therefore there aren't many points within the vehicle where you can grab 12volts with the ignition off.

However, I hard-wired a dashcam in my CR-V a little while ago and it took ages to find a 12volts permanent feed but eventually got one using a multimeter....sorry can't remember which circuit it was though....may have been interior lights.

They are there in the fusebox but will require a multimeter to find it