Should have mentioned my machine has a cab, looking for switched power inside the cabfront or back? if you are looking in the back there are two bullet plugs that are switched with ignition on. I believe they are good for 10 or 15 amps. While looking at the hitch, you'll find them in the top 3rd of the right side harness.
adding a sub woofer to the stereoYou might get better answers if you clue us into what you need the keyed power for....