Trailer Wiring Harness Installation - 2011 Mazda CX-9

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How to Install a Trailer Wiring Harness on a 2011 Mazda CX-9


Speaker 1: Today on our 2011 Mazda CX-9, we're going to be taking a look at and showing you how to install the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part number 56016.Here's what our wiring looks like fully installed, and it's going to give us all the required lights to tow our trailer down the road, including our clearance lights, turn signals, and brake lights. When we're not towing it, it's going to store nicely out of the way right here in our spare tire compartment. Whenever we are ready to use it, as you saw, we can just pull it out, drape it down, and hook it up to our trailer.Now that we've seen how our wiring looks after it's installed, let's go show you how we got it installed.To begin our installation, we're going to open up our rear hatch, and we're going to need to remove the floor covering right here. So we can simply just fold up, and then we're going to have to pull this panel out underneath where our spare tire tools are. We come to this cover back here and we lift up and actually take the whole cover and we're going to set it aside. We're also going to need to remove this cover as well, and we'll set it aside too.On each end of our cargo area, right towards the back of our hatch, we're going to have these cargo hooks.

If we rotate it up, we're going to have a fastener recessed inside, and we're going to need to remove it. I'm going to be using a 10-mm socket to remove them. Once we have the bolt removed, we can pop the whole cover out, and we'll repeat the same process on the other side as well.Just forward and slightly above our tie-down hook, we're going to have another spot where there's going to be a Philips head screw, and we're going to need to remove that. I'm going to be using a Philips bit to remove it. Now I have this side done, we're going to do the same thing on the other side as well.The threshold right at the end of our hatch area is going to need to come out, too.

If we come to either end and we just slightly pull straight up, it'll release the clips and we can set this panel aside.Further in in our hatch area, right here about the corner, we're going to have another tie-down hook right here, and we're going to need to remove this one as well. Now, there is a cover on it, so you can either take a flat-head screwdriver and pry that cover open, exposing the fastener. I'm going to be using a 10-mm socket to remove it. Once we have the fastener removed, we're going to do the same thing on the other side.Now, we're going to have to gain access behind this panel in order to get to the wiring for our taillights. If we come to the bottom of our panel and we start slowly pulling away, you can hear and feel the clips releasing, and you just want to work your way up and be very careful not to break the clips or tabs.

You don't want to pull too much, but our wiring harness is going to be right here, attached to the inside of the body of the panel. Now, there's going to be a small tab on the connector right here. Go ahead and push in on that tab. It should release the connector, and we can slide it out. Now, we can go ahead and grab our wiring harness and begin to make our connections.Since we're over here on the driver's side, we're going to be working with the yellow, red, and brown wire connectors.

If you notice, our connectors are going to look very similar to the ones that are on our vehicle. So instead of plugging them back into each other, I'm going to take my female end and plug it into the vehicle, and then the other end I can go ahead and plug into the taillight side. We're going to leave our wires tucked back there nicely for now, and we can bring our attention to the white wire with the ring terminal on it.We're going to need to find a suitable spot for our ground location, and I think if we find a nice spot, somewhere in here would be a good spot because it will be behind the panel out of the way, but we can still have room to route all of our wires. Now, to ground our wire, we're going to be using the provided self-tapping screw in our kit, and I'll be using a quarter-inch nut driver to put it in place. I'm just going to go right down here on the bottom of the floor.With this side connected and our ground connection made, we're going to take our green wire with the T-connector and route it towards the passenger side. I'm just going to run it along the threshold here. Once we have our wire towards the passenger side, we're going to have to grab that panel, just like we did on the other side, and start pulling it away, releasing the clips. That's where we're going to find our other taillight connector.Now again, we're going to have the same kind of connector on the right side, so we're going to go ahead and push in on that tab, which will release our connector. Then we can connect our green wire. With our excess wire, I'm just going to tuck it behind the panel, and we can secure our panel.We should have two wires coming off our black converter box here, our 4-pole trailer connector and a black wire. Now, our black wire we're going to have to connect to some more 12-gauge wire that they provided us in our kit, and we're going to have to run this to the battery. But before we do that, I'm going to strip back the end of this piece of the wire, and I'm going to take the butt connector provided in our kit and crimp it into place. Now, with the other end of my butt connector, I'm going to go ahead and connect it to that black wire coming out of my converter box, crimp it in place, and give it a nice tug to make sure everything's secure.Now, we're going to have to find a way to get the other end of our wire here to the outside of the vehicle. Fortunately, if we look to the outer edge of our floorboard here, we're going to have a grommet. I'm going to take a flat-head screwdriver and pop that grommet out. I'm going to hold onto this grommet, because once we get our wire ran down through, we'll go ahead and reinstall it. We can take the end of our wire, drop it down, and start feeding it through. Once there's enough wire underneath, we can go ahead and grab it and start pulling the rest of the wire.Now that our wire's through, I'm going to take a pair of side cutters, and I'm actually going to cut a slit in my grommet. That way it has room for my wire to slide through. Then we can take, slide it over, our wire, and we can reinstall the grommet, put it back in place. They even provided us a little bit of black silicone in our kit, so I'm going to apply a small amount to the grommet, since I did have to cut it. This'll help seal it up so you don't have to worry about any contamination or moisture coming up from the underside of our vehicle.Now, for our converter box, our kit does come with some double-sided foam tape to help us secure it down. I'm going to take the backing off of one side, and I'm going to stick it firmly to the back of my converter box, pressing, making sure it makes good contact. Then I can remove the backing off the other side. Then we're going to need to find a nice flat spot. Right here at the corner looks like a great location, because it's nice and out of the way. I'm going to just push against my box, making sure that glue sticks nice and good. As you can see, it's not going to interfere with the panel or anything else.With all those connections made, we can go ahead and start to begin to put this panel back in place. Now, I'm not going to put all my hardware back in. I'm just going to pop this panel back into the clips. That way I don't have to worry about it coming undone or catching on anything.Now, that black wire that we dropped down to the outside, we're going to need to run up to the vehicle's battery. Everybody's going to do this a little bit different, so let me get my wire ran, and then I'll show you how I did it. I just want to mention you want to stay as far away from any heat sources or moving parts as you can. I took my wire, I went over my rear axle, followed it down, tying it to some existing lines and wiring. Then I followed my emergency cable down. Then I went underneath this panel and followed that all the way down until it finally came out right here, and I dropped my wire right here.The way I'm going to get my wire up is that I took a piece of airline tube that I had laying around, and if you don't have this, you can use a coat hanger or anything that's just going to keep its shape. I'm going to route my airline tube down the engine bay until it comes out the bottom, close to where my wire is. Now, you just want to be mindful and make sure that you're not rubbing up against any heat sources or any moving parts. It may take a little bit of patience to get your airline tube or coat hanger or whatever you're using to get where you want it to go.Here's where my airline tube came out. I'm going to take the end of my wire, and I'm actually going to insert it into my airline tube to help secure it. Then I'm going to take a small amount of electrical tape and tape it up, so hopefully I won't drop it when I start pulling it up. I'm going to go back up top and pull our airline tube up. Once we get it all the way up, I'm going to secure it with one zip tie just to make sure it doesn't fall back down. It's always a good idea to double-check yourself and go back under, or even just take a peek underneath and make sure you didn't get your wire knotted up and have a big wad hanging underneath.If the wire's secure, we can go ahead and start to make our next connections. Now, this is a fuse-protected system, so we're going to have to put in our fuse holder. I'm going to go ahead and cut the excess wire back a little bit, and then I'll strip it back. Again, I'm going to take one of the provided butt connectors in our kit, slide it over my wire, and crimp it into place. Now, on the other end of my butt connector, I'm going to take my fuse holder. These are already pre-stripped, so you can just slide the end off and go and insert it into our butt connector and crimp it in place.On the other end of our fuse holder, our kit, they're going to provide us with a ring terminal so we can secure it to our battery. We're going to slide our wire in and crimp it down.Now, we're going to need to secure this down to the positive post on the battery, so I'm going to remove that nut and slide it on. I'm using a 10-mm ratcheting wrench to loosen up that nut. If you don't want to take the nut all the way off, we do have the option, if we take our ring terminal and if we just cut a small notch out of the ring just like that, you can then slide it over the bolt, the fuse holder in place, then take the provided 10-amp fuse and we're going to put it in the holder.Now we can go back to the back and start putting all the panels back that we removed in the beginning. For our green wire going across the threshold, I'm actually going to take a little bit of tape and secure it to the body right here, because that panel is going to cover it up. This way it'll just help keep it secure a little bit. You just want to make sure that you're not going to cover up any of the holes that the panel has to clip into.And my 4-pole flat trailer wiring connector, going to put in this panel to the left because there is a slight cut-out right here and I can just run it up here for now. Put the main panel back in place.On our tie-down hooks, if you notice, we're going to have a small tab. We're going to want to make sure to put that in the hole that there's no threads so that we can get our bolt back in place.With all our panels back in place, we can take our dust cover and we're going to slide it over the end, and then we're going to put the cap over the end of our connector. We can go ahead and store this right here in our spare tire compartment. That way it'll be ready whenever we're ready to tow.One final step is going to be testing it. I've got a 4-pole tester here. If you want to pick one of these up, you can use part number I26. I'm going to grab an extra set of hands so they can run the lights for me, so I can make sure everything's working properly.Can you turn the headlights on, please Looks good. Left turn signal Good. Right turn signal Good. Now the brakes. And finally the brakes and both turn signals. Looks like everything's working properly and we're ready to hit the road.That'll finish up our look at the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part number 56016 on our 2011 Mazda CX-9.


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