HOW TO: Install Powered Seats in 2016-2019 Tacoma

Hey Y'all,

I recently completed a retrofit installation of the electric-powered seat from a 2022 Tacoma into my 2017 TRD OR Premium. This guide should work for all 3rd gen (with heated seats) from 2016 to 2019 that want to install a 2020-2023 electric heated driver's seat. Passenger seat is 100% plug and play, no different than what's already in your truck. Back seats, too.

Background: I was planning to get seat covers for my stock seats, as they started to have a little wear and was also planning to get seat jackers for my legs. Clazzio seat covers and seat jackers were going to run around $750, but I managed to score a seat of all leather seats with electric driver from a 2022 for $550 and jumped on it immediately.

Where I differed from most people who had installed these seats: I used a simple wiring harness with a built in relay and control switch, as well as fuse. Most folks are connecting straight into the truck's wiring harness via the 30A fuse (pictured below) that is there for seat power from the factory, but I did not want to tap or splice into that source with aftermarket wiring for two reasons:

1. The power is always live and I didn't want any chance of the seat always having power accidentally draining the battery if we're ever out camping/traveling, so I wanted the ability to cut power to the seat motors if I chose. Since seats are rarely moved once set, this seemed like a no-brainer good move.

2. 30A on a wire tap or splice with smaller gauge wiring felt like a prime situation for a potential fire and I would like to avoid that. After doing aircraft electrical work in the Air Force for years, I'd rather be safe & simple than sorry.

What I used:

-

$16 Nilight 10018W 14AWG DT Connector Wiring Harness Kit Bar 12V On Off Switch Power Relay Blade Fuse for Off Road LED Work Light-ONE Lead

Nilight AUX Light Wiring Harness (with 15A Fuse)
- Two 12-14 Gauge Heat Shrink Splices
- 3M Automotive Double-sided tape
- Zipties
- Electrical Tape
- New Seats
- Coors Light (for morale)
- 14MM Socket & 3/8 Ratchet (back seats will need 12MM, 10MM if you replace those)
- Trim Tool

Step 1 - Disconnect battery and let truck sit for 5-10 minutes. Airbags are sensitive and I would like to not get smacked in the face.

Step 2 - Unbolt driver seat and disconnect plugs under the seat. Remove the seat from the truck. They should be 14MM. Trim tool may be needed to pop the harness holding plugs out of the seat frame.

Step 3 - Set the new seat and old seat next to eachother to understand the layout of the plugs and harnesses.

Here you can see the new seat on the left and old seat on the right.


Here are the two seats side by side with the plugs and instructions on where to connect:



For context, here's another picture of the new seat closer up:



Step 4 - Set the new seat in the truck and connect all the plugs from the truck's portion of the harness to the new seat. BA3 will be left alone at this point and IE3 should be dangling, you can see it in the most recent picture above, it's the left one behind the core support.



Step 5 - Peel back the loom covering from BA3 and expose the wiring. The FAT PINK wire is your ground wire for all seat motors. The FAT BLACK wire is your positive/power wire for all seat motors. All other pins/wires in that plug are not needed.



Step 6 - Splice in the wiring harness plug black ground wire to the FAT PINK wire on BA3. Splice in the wiring harness red power wire to the FAT BLACK wire on BA3. Apply heat to the splices and then wrap in electrical tape. You can also use new corrugated plastic loom covering if you wish. This is what it looked like when I was finished:



After this, I wrapped BA3 and IE3 in electrical tape as well, just to protect against any spilled drinks or random water getting in there, ya know....safety and stuff.

Here's a picture from Shveet (TW User) that he drew of the plug pinouts and wiring to get a good idea on it:



The full OEM wiring harness diagram is here:


Step 7: Install wiring harness in the engine bay. I connected the power wire to the top of the + Battery Terminal and the negative wire to the factory ground just right of the battery.

I also installed the relay on a bolt right next to the fuse box so it was out of the way.

Step 8 - Pull the switch wiring and harness wiring through the rubber passthrough on the firewall. I attached zipties to each one and poked it through to have something to pull it through.



Step 9 - Run the wiring under the carpet, zip tie to the OEM loom, and bolt down the seat! That part is completely done.

Step 10 - Clean up the wiring in the engine bay so we don't look like cavemen working on our vehicles.



Step 11 - Stick the switch for the power to the seat anywhere you like. I thought the sticky backing it came with was not very strong, so I replaced with 3M tape. Totally up to you. Here's what it looks like on the dash. I tucked it close to the TPMS switch and you barely notice it's there. The switch will always have power, but you can cut power to the seat and protect your vehicle. Also, a 15A fuse is PLENTY for the seat. You do not need a 30A fuse and I would recommend not using one that high!



Step 12 - Reconnect the battery, close the hood, and crack open that Coor's Light and enjoy your new power driver seat!!

PS - The seat heater wiring is separate from the BA3 seat motor plug, so your buttons on the dash will control seat heaters as normal.




I want to give a big shout-out to a lot of members on the forums for all of their help and sharing how they connected their electric seats and completed the retrofit: Shveet, MaverickT883, caribe makaira all posted incredible information that helped me figure out exactly how to do this.

 

Nice install.

 

Thank you!! I read the other threads and got honestly really confused until a couple users (Shveet and Maverick) helped explain what they did since I didn't want to have 30A constantly on and live under my seat. I'll be upgrading to an Auxbeam panel soon and just have this seat wired in.