I plan to install a PLX DM-100 touch gauge using the Roush vent mount. Seems like a fairly easy job to do, but the one thing I haven't been able to figure out is where to tap into switched +12V so that the gauge turns on and off with the ignition.

Any hints are most welcome.

EDIT: Sorry, probably wrong forum. Should be in '10-14 Interior and Audio, I guess.

 

The radio circuit is switched, maybe that can be located easily.

 

There is switch power in the inside fuse box on the passenger side. You can use a tap a fuse, but be warned unless your skinny its a pita to get to it.

 

That's exactly what I ended up doing. The tap a fuse works great, except that the fuse cover cannot be put back on.

I used fuse 37, by the way. A spare one that is hot in start and run, exactly what I needed.

So far, the gauge works great.

 

You had to get creative. I passed the two wires, since using two tap a fuses one switched other constant, through the vents in the fuse box cover and with the correct selection of fuses the cover fits fine.