TrailerMate Tail Light Wiring Kit for Towed Vehicles Installation - 2011 Mercury Mariner

How to Install a TrailerMate Tail Light Wiring Kit for Towed Vehicles on a 2011 Mercury Mariner

Today on our 2011 Mercury Mariner, we'll be installing the TrailerMate Custom Taillight Wiring Kit for Towed Vehicles, part number TM782055. To begin our installation, we'll need to open the rear tailgate and, using a Phillips screwdriver, we'll remove the screws holding the taillights on the driver's side as well as the passenger's side. There are 2 on either side. We'll then pull the taillights backwards, away from the vehicle, to disconnect them from the vehicle itself. These clips do hold on tight, so it may be necessary to use a little bit of force, but do be careful as you can break the taillight assembly. Starting here on the driver's side, we'll take the connector containing the yellow wire and plug it into our driver's side taillight wiring.

This is the vehicle side. We'll then take the entire harness and slide it down underneath the vehicle between the bumper fascia and the back of the vehicle. You'll notice the white wire here with the ring terminal on it. This is our ground. Here behind the driver's side taillight, we're going to go ahead and use a self-tapping screw and after finding a suitable location, we'll use the screw to drill the hole and tighten it down, making our ground connection. Now we're underneath the vehicle.

Here on the driver's side we'll reach up and pull the harness out from behind the fascia. We'll now take the part of the harness that is covered with the corrugated protector and run it along the rear bumper between the bumper and the fascia itself over to the passenger's side. Here on the passenger's side, we're going to go ahead and run our harness through the bumper itself just to keep it out of the way of the heat from the tailpipe. We'll then run it up between the bumper fascia and the back of the vehicle to the passenger's side taillight harness. Here on the passenger's side, we'll pull up the connector and connect it to our vehicle harness. With that done we can go ahead and re-install our passenger's side taillight.

Once connected, the T-connector will be between the vehicle harness and the taillight assembly itself. After making all our connections we'll re-install the passenger's side taillight and do the same here on the driver's side. We'll now move back underneath the vehicle where we'll need to route our 4-pole wire up to the front of the vehicle. We're going to go ahead and follow the brake lines as much as possible as this will take us all the way up to the engine compartment. Along the way we'll use the zip ties that will secure the 4-pole harness to the brake lines periodically.

Make sure that you keep the harness away from any moving components, such as the vehicle suspension, or hot components like the vehicle exhaust. Now we'll continue running our 4-pole harness up and here we'll need to take down the undercover just so we can get our 4-pole harness through. We'll now pass the harness through the core support and out here to the front bumper. We'll then go ahead and re-install our undercover carriage as well as clip off any of the excess zip ties, giving us a nice, clean look. Here up in the front, we'll tie up our excess 4-pole wire harness using an additional zip tie. With that out of the way we can then use the bracket supplied with the kit after modifying it slightly and attach it to our base plate. We'll then put the 4-pole harness into our bracket which will complete the installation of the TrailerMate Custom Taillight Wiring Kit for Towed Vehicles, part number TM782055, on our 2011 Mercury Mariner. .