12Volt Switched Power Source in Mk5 Fiesta Facelift

**L14M333** · 09-04-2011, 12:18 PM

First off i'm new to the forum so please correct me if i've done anything wrong

Hello... I've got a 2000 Mark 5 Fiesta (Facelift) and I am looking to power two USB chargers what I have internally fitted in my car...

In the fiesta I have, the cigarette lighter socket is a constant 12V feed what still can draw power when the ignition is off and I don't want to keep the chargers powered if the car is off and accidentally leave something plugged in and come back to a dead car battery so I need to find an alternative.

I did add a terminal connector to the switched live feed of my car radio to see how that went but the cabling for that source is only build to hold very little current and i managed to burn the cable out accidentally so this isn't an option any more.

So I was wondering if maybe anyone else has an idea on where I can get a source what can power what I want only when the ignition switch is on? Maybe I can use the heated seating circuit from the ECU as my car isn't equipped with heated seats? Or maybe I can build some sort of circuit what will only allow power through if it is receiving a voltage from the switched feed but wont pull the current from the switched feed itself?

It would be great if somebody that has done this can help, even better if they have done it in the same car!

Thanks in advanced

Liam

**kegobeer** · 09-04-2011, 12:44 PM

I'd run power from the battery to a standard 30A automotive relay, and trigger the relay with the IGN wire on your radio harness. Or, if you aren't going to be drawing a ton of power, tap into your fuse box and grab power for the relay from there (either an unused fuse, or by installing a fuse tap).