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Trailer Brake Controller Installation - 2003 Toyota Tacoma

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How to Install a Trailer Brake Controller on a 2003 Toyota Tacoma

Today on this 2003 Toyota Tacoma, we're going to show you the Tekonsha Primus IQ Trailer Brake Controller, part number TK90160. Now to help us with our install, we're also going to use part number ETBC7. This is a universal installation kit for trailer brake controllers. For the majority of our install, we'll be using this part number and then we'll take our brake controller and add it on top of this as our last part of our install. This is what the Primus IQ looks like when it's installed in our truck. Now we have it in a typical location here on the right hand side underneath the dashboard. This style brake controller is a proportional brake controller, which means that when you hit the brakes on your truck, there's a sensor on the inside that can tell how hard you're hitting your brakes.

That in turn sends the appropriate amount of power out to your trailer brakes. That total amount of power is set by the user. Let's go ahead and cover some of the features. When you have the trailer hooked up, it shows a C for connection and it gives you a little bit of a diagnostic to make sure that your trailer is still electrically connected to your truck as you go down the road. Then when you don't have it connected, you'll get the NC for no connection. Over here is the manual override, if you ever need to activate the trailer brakes by themselves.

On the back on our left side here, we have a little wheel right here. That controls the total output of power going to the brake controller. If you scroll all the way back towards the back our our truck, we can see it displays two zeros, so that means there's no power going out to the trailer at all. I'm going to scroll back up and pull the manual override over, we can set our total power output. Typically, you'll start somewhere in the middle and then work your way up and down, depending on how heavy your trailer is. Typically, the heavier the trailer you have, the more power you'll need to send out to your brakes.

On top here is our boost button. If we scroll through it, it will say B1 for boost one, B2 and B3 and the fourth setting is actually no boost. The last little detail in the display, is you'll notice there's two dots. One dot will show that it has a boost setting. The other one shows that we have power going to our brake controller. When we install our brake controller, it can be completely flat on the bottom or it can tilt up to 70 degrees.

The brake controller comes with two brackets. We're using this bracket here that allows the brake controller to be easily removed. The other bracket makes a little more of a permanent install. What's nice about this bracket is you can take it off by unsnapping the brake controller from it, pulling it away and you can actually easily disconnect it and if you need to, you can transfer this to another vehicle. Next we'll go ahead and show you how we install the Primus IQ Brake Controller. First thing we need to do is go ahead and find a location for the bracket for our ETBC7 kit. Our seven pole connector will fit on this bracket here. To help us attach our bracket to the rest of our vehicle, we're going to need to use a universal mounting bracket, part number 18140 from Tow Ready. That's going to sit right here and there'll be a clamp for it that will hold it in place. We'll run the clamp back through itself and take up the slack and then push the catch up. Then we can go ahead and tighten it down using the 5/16ths nut driver. Using the hardware that came with our universal bracket, we'll attach our seven pole bracket. We'll tighten it down using a Phillips screwdriver. Now using the hardware that comes with the seven pole bracket and connector, we'll go ahead and attach the two together. We'll tighten these guys down with a flat blade screwdriver. All right, let's go ahead and take a moment and bundle up our wires behind our seven pole connector. I'm going to just use some loose wraps for our electrical tape and we'll use some loom material that comes with the kit to bind it together just a little bit more. We'll continue wrapping these two wires here, white and our purple wire, together to help keep them bundled. The back side of our seven pole connector has a four pole wire harness, that's designed to plug into your preexisting four pole wiring on the vehicle. This provides the running lights and turn signals and brakes. We'll put the two together. Before I do that, I like to add some dielectric grease. We're using part number 11755, Lubrimatic Electrical Contact Grease. Once we have it pushed together, we'll go ahead and add some electrical tape around it, since this will be somewhat of a permanent connection at this point, because our seven pole connector also has a four pole on the outside as well, if it's ever needed. Next up, there's a white and purple wire. Our white wire is going to provide ground for the whole electrical system for our towing harness and our purple wire is used for an auxiliary circuit, so if you want additional power wire for whatever reason out to your trailer, you can use this. Also, typically this can be used for reverse lights on your vehicle, however in this case we will not be needing this, so we'll just leave it with the ground for a future upgrade. I'm going to take my ground and basically I'm going to attach it to the frame about right here. We'll use the provided ground screw that comes with the ETBC7 kit. We'll need a 3/8ths nut driver to install it so I'm going to go ahead an put my screw in first and then attach my wire. Next we'll go ahead and work with these two wires right here. Our black wire will provide a 12 volt power supply for anything on the trailer. Our blue wire will be our output from our brake controller. We're going to connect up the gray cable that comes with ETBC7 kit to these two wires. Let's go ahead and strip the sheath back on our wire. We'll go ahead and strip the wires back. Let's go ahead and connect these up to our wires. All right, now unfortunately we don't have an exact color for color match but we'll do the best with what we have. We'll go ahead and make our wires black to black and white to blue. What will happen eventually is our white wire will go back to the blue wire on our brake controller. Since these are outside the vehicle, I'll go ahead and use some electrical tape to help give it some extra protection. Next we'll go ahead and take our gray cable here and we're going to run that up to the front of the vehicle. When we do that, we want to stay away from anything moving like suspension components or anything hot like the exhaust. Also, once we get to the front of the vehicle, we want to stay away from the steering components as well. Everybody's going to run their wires a little bit different, but this is how we did ours. We started at the end of the frame here and ran it over some of the supports for the frame that go across and basically we just followed some wiring and some lines going up towards the front, basically staying along side the frame. We ran it up inside along the gas tank and towards the wiring and used lines once again and just worked our way up towards the front. Then we just kind of left it here in this little handy loop. Next we'll go ahead and take a few moments to go ahead and zip tie our wires at the back to secure them. Then we'll pull this up towards the top. Let's go ahead and pull our wire up. To help us do that, I'm going to use an old piece of airline tubing that we'll route down from the top towards the bottom. This also could be a piece of wire that can hold it's shape as you can run it down towards the bottom. There seems to be a nice opening behind the brake booster here. We'll go connect our wire and pull it back up, then we'll send it up towards the top. Next we'll go ahead and install our circuit breakers. The ETBC7 kit comes with three circuit breakers. We're going to use a 40 amp circuit breaker for our black wire going out back for our power supply for our trailer and then we're going to use a 20 amp circuit breaker for our brake controller. Depending on the application, your brake controller may need a 30 amp circuit breaker. We're going to mount in this location right here. We'll use a provided self tapping screws to attach it to the sheet metal and we'll need a quarter inch nut driver for that. Our 20 amp circuit breaker will overlap with our 40 amp circuit breaker and install screw. Next we'll go ahead and work with our gray cable once again. We'll route it from our 40 amp circuit breaker over to our 12 volt power supply, which will be the positive post on our battery. This will be for our black wire. Now our white wire will also be ran to the inside to the output of the brake controller, so we'll add some extra length to it so we can go on to the inside with it as well. Then we'll cut off our excess. Our excess we'll need to save because that will be ran from our brake controller back up to the power supply as well later on. Let's take a few moments to go ahead and separate our wires. Let's take our wire wire and we'll just separate off to the side for now. Let's go back to our black wire here and we'll go ahead and cut the wire in half, add our two small ring terminals that will go to our circuit breaker and then one large one that will go out to our battery. This large ring terminal going to our battery, I'm going to leave that as one of the last connections we make. The other end of the wire, we'll attach to our circuit breaker. When you hook up the wires, you want to make sure that you take a look at the labels on the post. One's labeled battery, so our wire going out to our battery will go to that post and other posts will say auxiliary, which will go out to your other device. In this case it will be the trailer and then this one will be our brake controller. We'll tighten down this hardware. Next we'll go ahead and work with our white wire here. We need to run this from the outside to the inside. To do that, we're going to go through this grommet right here. We'll take a razor knife and along the top edge here, kind of in well, you can go ahead and make your cut. Just make sure you try to stay above the wires, we should be good to go. We'll poke our wire through to the inside. Now we'll get our excess wire, still on the gray cable, we'll run that in as well. I'm going to actually tape it to our white wire here, and use the white wire to pull it through for us. Let's go ahead and make sure we have enough length in our wire and we'll go to our circuit breaker and then back up to our battery once again. Once we have that length, we'll go ahead and separate two wires one more time. We'll just do a small section up here so we get access to our black wire. Just like before, we'll cut the wire in half and add the two ring terminals. Let's go ahead and connect up to our circuit breaker. Let's go ahead and route our wires up towards our battery now and then for the ends of our wires, we'll add the last two large ring terminals. The two black wires go to our positive side and our white wire will go to ground, which we can go to the battery, but we got a really convenient ground right here to use. Again, we'll leave these connections as last. Let's go back inside the vehicle and we'll work with our wires on the inside now. We'll go ahead and cut off some of our excess length. Now we can go ahead and start working with our wire harness for the Primus IQ Brake Controller. This actually plugs into the back of the brake controller and we'll go ahead and hook up our wires from here. Let's go ahead and get our wires ready. We'll go ahead and strip them back a little bit more and we'll use some of the butt connectors from the ETBC7 kit that are left over to make these connections. Let's go ahead and hook up to our wires from the outside. Let's start off with our easy one, which is our single white wire. Remember, that was our only single white wire for our output from our brake controller. That will go back to blue. With that one little confusing thing out of the way, now we have our cable left over for our power supply from our battery. These just simply match up color for color. Now our last wire is a red wire from our brake controller. This needs to get power from the cold side of the brake switch, which means when we hit the brake pedal, this wire will get power. That's also what turns on the brakes from the back of the vehicle. Our brake switch we're going to need to attach our wire to is way up on the brake pedal here, so we're going to have to definitely add a little bit extra length of wire to this. I'm going to use some extra red wire that I had in the shop here to do that. Go ahead and use a butt connector from the ETBC7 kit once again for this wire. The butt connector's a little bit on the large side, so we'll strip the wire back a little bit extra and fold it over to give it some more surface area to grip. Now for our other end our our wire to make our connection, we're going to use a quick splice connector. Basically this will slip over the wire that we want to tap into. This wire here, red wire, will go right next to it on the other side and we'll squeeze the metal clip and that will connect the two together. Now since it's pretty far up there, we'll go ahead and show you where to look first and then we'll go ahead and make our connection and show you afterwards, because there's hardly any room up in there. We'll follow our brake pedal all the way up, here's our switch right here and these are the wires we need access to. Now when we hook our wire up, we found that the dark green wire with the white stripe is the brake signal that we need. At this point, we can go ahead and start working with our brake controller. We need to install our bracket to hold the brake controller in place. This is a matter of personal preference, however we do need the brake controller to stay in a straight line with the vehicle and with hardly any twist at all. First we'll go ahead and set up our bracket to those standards. We'll go ahead and put it up to the bottom of our dashboard here on the right hand side. We'll try and match up the curve on the bracket with the curve that's on the dashboard where the screw goes in. We'll use the provided self-tapping screws to attach it to the plastic. With our bracket in place, we'll go ahead and hook up our brake controller. We'll take the wires that we had just installed, plug into the back of our brake controller. There will be some notches in the brake controller that will match up with tabs that are in the bracket. We'll line those up, push that into place and then we'll bring it up and it will snap in. Once we have it snapped into place, we can go ahead and cover up some of our wires with some leftover loom material. We'll go ahead and zip tie the rest of our wires to keep them safe and secure and out of the way. The last two connections to make, we'll go back up to our battery. We'll go ahead and loosen up this nut on the positive post and hook up our two power wires. We'll reinstall the nut and we'll need a 12 millimeter socket to work with this hardware. Then we'll go over to our ground wire, which we'll need a 10 millimeter socket for. With that, everything's connected up, we'll go ahead and give it a quick test. Let's go ahead and check out our brake controller. We can see we got two dots here. This dot here tells us we have power going to our brake controller. This one tells us we have a boost setting so we have that going. Let's go ahead and check the manual override. It says NC for no connection, so that means we don't have a trailer hooked up, which is good. Let's go ahead and hook up our trailer and then try it out that way. Now we've got our trailer plugged in, we can see we have on our display that shows a C for connection, which is a good sign. We'll go ahead and check the manual override. You can see how it scrolls through numbers, so that's a good sign. We'll go ahead and try our foot brake and it shows us some numbers there too, so it tells us that our foot brake connection is working. Now all that's left is go ahead and take the truck and trailer for a short test drive and set up the brake controller so it activates the brakes the way you want it to. With that, that will finish it for our install of the Tekonsha Primus IQ Trailer Brake Controller, part number TK90160 on our 2003 Toyota Tacoma.

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Info for this part was:

Test Fit:
Joe V
Video Edited:
Zack K
Video Edited:
Andrew K
Installed by:
Jeff D
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Joshua S
Test Fit:
Nicholas E
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Jacob T
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Andrew L
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Kathleen M
Video Edited:
Mike H
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Dustin K
Installed by:
Cole B
Test Fit:
Shane T
Test Fit:
Alan C
Video Edited:
Sue W
Test Fit:
Randy B
Video Edited:
Chris R
Test Fit:
Jared G
Video by:
Zach D
Test Fit:
Andrew S
Test Fit:
Brent H
Test Fit:
Shane H
Test Fit:
Robert C

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