Toyota Tacoma: How to Install Heated Side Mirrors

Just because your Tacoma didn't come from the factory with heated side mirrors doesn't mean you can't have them! Check out our DIY guide on installing heated mirrors on your truck.

By Brett Foote - January 27, 2016

This article applies to the Toyota Tacoma (1996-2015).

Heated side mirrors are one of those little luxuries that you never knew you needed until you see them in action. But when things get foggy or icy outside, it's a nice little feature to have and it gives you one less thing to worry about when you're trying to brush off snow or scrape ice off your windshield. Even if you didn't have the foresight to buy a truck with factory installed heated side mirrors, you can swap a set onto your Tacoma. All it takes is the better part of an afternoon and a laundry list of parts.

Materials Needed

Toyota Highlander or Sienna mirrors (one left and one right)
Highlander mirror switch
Highlander mirror switch plug
Toyota or Sumitomo terminal leads (5)
10 amp fuse tap
SPST or SPDT relay and plug
14-16 gauge quick splices, butt connectors, and 1/4" ring terminals
.110" 16 gauge female spade connectors
.187" 16-22 gauge male and female connectors
30" 16 AWG primary wire
Heatshrink tubing
Wire crimping tool
Needle nose pliers
Phillips head screwdriver
Flat head screwdriver
Panel removal tool
Zip ties
Electrical tape
Coat hanger
Scissors or knife
Torx bit driver/wrench
Dremel
Vice grips
10mm socket

Step 1 – Remove the factory mirror glass

Pop the hood and disconnect your battery before getting started, which will prevent any "shocking" surprises later on. Press down on the top of your side mirror gently until there is a gap on the bottom. Slide a flat head screwdriver into the gap and pop the mirror glass out from the mounting plate.

Figure 1. Push down on the side mirrors and insert a flat head screwdriver to the point shown.
Figure 2. A better view of the white mounting tabs.

Step 2 – Prepare/modify new mirrors for installation

If you are using the Sienna mirrors, you can skip this step because the 2012 Highlander heated mirror glass is a direct replacement for the Tacoma. Otherwise, you must first remove the back plates from the mirrors and modify them to fit. Heating them with a heat gun or hair dryer makes them a little easier to remove, and a credit card can be used to pry the glass off the backers. Next, you will need to widen the hole on the Tacoma back plate to accommodate the terminal leads on the Sienna mirror using a Dremel or similar tool. Install the Sienna mirrors on the Tacoma back plates.

Figure 3. Remove the back plates from all the mirrors.
Figure 4. Remove the glass from the new mirrors.
Figure 5. Widen the holes on the Tacoma back plates.

Step 3 – Assemble the circuit

Use the schematic in Figure 6 to properly wire up the relay for this circuit. Quick splices make this a much cleaner and easier job. You will need to splice into the dimmer wires from the fog light switch to connect the switch plugs. If desired, you can heat shrink these connections and solder them for a little more secure connection.

Figure 6. Use this schematic to wire up your relay.
Figure 7. Use a quick splice, as shown, to speed up the process.

Step 4 – Run mirror leads

Remove the door panels, kick plates, dash, and glove box. Remove the speakers from each door and unplug the mirror plugs. Remove the side mirrors from each door, take them apart, and remove the plug cover. Connect the .110" female spade terminals to the Sienna mirror tab terminals and feed both leads through the shield. Crimp a 1/4" ring terminal on each 30" mirror ground lead, then ground each mirror to a bolt inside the door (see Figure 9). Feed the 12 volt mirror lead through the door into the cab.

Figure 8. Connect the spade terminals to the tab terminals.
Figure 9. Ground each mirror to a bolt in the door.

Step 5 – Install the circuit

Mount the relay to the left of the brake pedal, where you will find an empty hole on a metal mount. Connect the driver's side lead into the plastic retainer of the hood clip cable (Figure 10). Use another quick connect splice to connect wire #5 (Figure 11). Secure the ground wire on a nearby metal plate and plug in the switch. Use the fuse tap to tap into the gauges fuse on the fuse box. Connect an 8" lead from the fuse tap butt connector to the quick splice from the #5 switch lead. Go back and make sure all wires are secure and zip tied out of the way, then reassemble your interior components and enjoy!