While under the back end working on stuff I did see what I suspect is the wiring harness for trailer lighting. What recommendations are there for a trailer plug? All I need is a flat four wire but in a money saving, parts re-purposing move I might use a multi plug off of a truck I parted out.

 

Any generic 4 pin flat plug should work just fine. You can buy them new with a little harness on them in most parts stores for pretty cheap. I've never seen one prewired for a 7 pin, so no point in installing that unless you plan on running some wire. But my 04 that didn't even have a hitch when I bout it had the plug already there (and a trailer ball in the bumper, which is a JOKE... I would HIGHLY recommend getting an actual trailer hitch 2" receiver to bolt to the truck if you're going to haul anything...). I installed a hitch myself, peeled back the covering on the wiring for the plug that was on it just to inspect it and make sure it was in good shape. All looked good, so I put some new split loom over the wire and a little electrical tape to hold it on, and it hasn't given me any issues in the 5 years since. And I use the heck out of it lol

 

Flat four plugs do not cost much at all and are very easy to install. A seven wire plug is easy to install if you are only hooking up the four wires you need to make the four flat work. If you are installing a brake controller, then that is much more involved. If you don't have a clue you might want to pay a shop to install the brake controller and wiring.

 

I considered hooking up a 7 pin and using the center pin as a constant 12v supply took keep a small battery charged up for a small ATV winch on the trailer. But honestly if I ever feel like I really need to install such a thing, I'd probably just forgo the small battery on the trailer and hook up a second dedicated connection with like 4 gauge wires and a high amp disconnect (Anderson plug) directly to the winch on the trailer, and just tie the other end on the Blazer into the 0 gauge that I already have running to the back seat for my old stereo setup...

Would be neat to have a constant 12v source on the trailer that could delivery 30+ amps so that I could run some lights on them. Sucks loading trailers in the dark lol

 

OK, here's what I'm looking at. And I'm only pulling a 14' aluminum boat with a light trailer so I'll most likely just go with the ball in the bumper. Total wt can't be much more than #500.

Flush Mount Trailer Plug

 

Personally, I wouldn't use the bumper ball for ANYTHING. If you're on a budget, you should be able to pick up a used receiver hitch pretty cheap. Even new ones aren't very expensive, and installation is pretty easy. It's a much better way to go.

All my trailers are 7-pin (even the ones without brakes), so I like the dual receptacles (7-pin and flat 4) that come on most newer trucks. That way, I'm good to go with most trailers that I might borrow or rent, too.