Was interested in IF you got it done, it had been three months and I was just wondering what and how you made out.
What you were asking for in the first post, Buggman answered, what you really wanted and stated in your last post is a little different.
I have How-To on Aux Lights, use it and in place of the Lights put the Power Port and instead of the switch find the type of power you want in the circuit panel and tap that fuse for power.
Don't set up an OEM Power Port for more than 10 amps, (that's MAX).
You can run 16 ga wire for the main power but the fuse needs to be 10 amps max, maybe an 8 amps fuse if you can find it; the reason is if you had a device that draws max current for a while it may heat up the OEM Socket.
The trigger wire for the relay, coming from the circuit panel can be 18 or 20 gauge wire and add a fuse there too.
Let see what else... Run the wires in between the dash and the lower part of the windshield area, feed the wires back to where you need them. Don't use a power port just hard wire the GPS wiring directly to the relay.
Maybe add an in line switch, a double throw switch so you can turn it on with the ignition off, if need.
HORNS, as stated the Hella Horns are good, what model, beat the $hit out of me, go to the hella site and check out their horns, come back with a model and name and there might be more response.
Some horns can use the OEM Wiring but some, to be loud enough, need a relay and a direct fused path to the battery.
One more thing, when some people read these threads, they read the postings and if there is an answer they don't bother to post, why be redundant.
Another thing... buggman posted adding a power port to the bezel, what do you have now and do you already have a power port ?
What year Ranger do you have ?