DIY – OEM Heated Seats

[@Art_Mighty]

(Disclaimer: Tampering with any part of car may void your manufacturer’s warranty. If you decide to perform the conversion you could damage your car or be hurt; you do so at your own risk, I am not responsible for damage or any harm you may suffer or any special or consequential damages)

This is my first attempt at a DYI so your grace is appreciated. I will update this with suggestions and corrections as time allows. I also won’t cover every step in detail as there are other posts which cover the removal of the center console and the seats themselves for example. Here are some bread crumbs for the noobies...

Console Removal
Seat Removal

I also assume everybody knows how to solder and use heat shrink tubing (no 3rd degree burns kids!)

This is expensive. The minimum cost of the upgrade being at least $1000 assuming you trying to retrofit BRZ seat cushions (the heaters are in the cushions themselves from what I understand) into FRS seats. A used set of seats could cost anything depending on their condition. New I believe their $2800 *EACH* as complete assemblies. Used BRZ limited seats do come up for sale on this forum and can be found at salvage yards. If you’re getting these used make every effort to get the plugs for the seats and their switches from the seller as these will be difficult to find on their own and prohibitively expensive to purchase as new parts as they come integrated into harness assemblies.

I was fortunate enough not only to find a set of BRZ limited seats but a seller who was willing to sell me his center console and allow me to snip off the four plugs from the cabling harness I needed for the two switches and the two seat heaters. Because this will not always be possible I will do my best to give enough information to accomplish this without those harness connections.

1) First study the wiring diagram.



The switches are at the “middle” of everything. Power flows into the switches and out to the seats. Both switches have grounds and so do the seat heaters. I decided I would ground the system to some bolts towards in the middle of the passenger compartment, near the yaw sensor, towards the “rear” of the center console.

I used only RED WHITE and BLACK wires to make my harness. Using a piece of rope I measured out the distances and then started cutting. You will need to make a harness with four segments:

A: From the switches to the fuse box
B: From the Driver Switch to the Drivers Heating Elements
C: From the Passenger Switch to the Passenger Heating Element
G: The Ground return from the two switches and the two heaters to chassis

I routed the segments for the drivers seat and the fuse box behind the parking brake handle and cables



2) Make and install the harness

I used the following measurements to make the harness:



I went out and got 16AWG wire (which was MUCH larger) then the 18-20AWG wire used by the factory. First I cut the wire to length…



…and then fed it thru heat shrink tubing….



…to make the each harness segment.



Solder the seat plugs to the (A) Drivers and (B) passenger side harness segments…



...and then solder the segments together, shrink the tubing and WA-LA!..



…You have a wiring harness!





3) Marvel at the product of your handy work!



A note about the power connection. Originally I wanted to tap directly into an existing harness wire. My thinking was that because the fuse was installed, so were some of the electrical connections branching out from the ECM but no Dice! So, I had to resort to fuse taps.



So what if you don’t have the harness connections? I took pictures of the plugs in their jacks so you would know which wire corresponds to which connection (see my modified wiring diagram above).




With some extra work and a trip or two to NAPA to find aftermarket four conductor male/female harness parts you can do this without cutting the connections from an existing harness.

Enjoy... :happy0180:

[@Art_Mighty]

Reserved

[iketiak]

Dude awesome DIY! so are both the back and bottom cushions heated or only the bottom portion?

[@Art_Mighty]

Originally Posted by iketiak

Dude awesome DIY! so are both the back and bottom cushions heated or only the bottom portion?

On high both the back and bottom, on low it's only one of them but its been too warm to test. I'll get back to you to confirm when it gets cooler

[ganjara]

Originally Posted by @Art_Mighty

On high both the back and bottom, on low it's only one of them but its been too warm to test. I'll get back to you to confirm when it gets cooler

Awesome stuff there. I have picked up some premium seats with heaters, my question to you sir: could I simply purchase the centre console heater switch and complete wiring to suit? Or is this to cumbersome too cumbersome and a pain in the ass to retrieve?

Too work mate and thansks for any input!

[@Art_Mighty]

Originally Posted by ganjara

Awesome stuff there. I have picked up some premium seats with heaters, my question to you sir: could I simply purchase the centre console heater switch and complete wiring to suit? Or is this to cumbersome too cumbersome and a pain in the ass to retrieve?

Too work mate and thansks for any input!

My advise to anyone trying this is the snip off the ends from the donor car and then work our a center consol swap as part of the deal.

If your trying to do this without the harness cable ends it's possible. I tried to leave what I would want as bread crumbs if I had to attempt this without those ends. It would probably require some dremmeling of the switches to expose the wires enough to solder them and something similar for the connections under the seat.

I REALLY wanted OEM heated seats so even if the harness cable ends weren't part of the deal I would have made them work.

[RojerLockless]

*opens the thread* Oh sweet I'd love heated seats! *sees all the pictures of wires* Well.. screw that lol

[ganjara]

Originally Posted by RojerLockless

*opens the thread* Oh sweet I'd love heated seats! *sees all the pictures of wires* Well.. screw that lol

Exactly... if it were plug and play I'd do it although in Sydney there's like 3 weeks of the year I'd even use them lol. Think I'll just use the seats as seats and the heaters can just go to waste. Bit of a shame though because I'd kinda like that extra plate in my centre console to have switches on it rather than empty space

[RojerLockless]

Originally Posted by ganjara

Exactly... if it were plug and play I'd do it although in Sydney there's like 3 weeks of the year I'd even use them lol. Think I'll just use the seats as seats and the heaters can just go to waste. Bit of a shame though because I'd kinda like that extra plate in my centre console to have switches on it rather than empty space

why not buy one of the cool plates that fit in the spot making it flush with the 86 logo?

[914_WHITE_FRS]

Originally Posted by RojerLockless

why not buy one of the cool plates that fit in the spot making it flush with the 86 logo?

where is that plate by the way!!???

[RojerLockless]

Originally Posted by 914_WHITE_FRS

where is that plate by the way!!???

http://www.ft86club.com/forums/showthread.php?t=45423

Great vender too. I keep wanting to buy one just going back and fourth on which one I want.

[lbroskee]

@@Art_Mighty what do you recommend if i can't get the connectors? or would you know the part numbers for them? I'm looking into this but since won't b able to source easily i need to improvise

[@Art_Mighty]

Originally Posted by lbroskee

@@Art_Mighty what do you recommend if i can't get the connectors? or would you know the part numbers for them? I'm looking into this but since won't b able to source easily i need to improvise

Sorry for the delay, I just read this. I posted (to the best of my ability) which wires were going where so in theory you can source your own connectors and improvise. You can PM me and I'll do my best to help...

[Figo]

Originally Posted by @Art_Mighty

Sorry for the delay, I just read this. I posted (to the best of my ability) which wires were going where so in theory you can source your own connectors and improvise. You can PM me and I'll do my best to help...

thank you for your thread!

Do you have any suggestion if I only need to swap seat to base FRS but do not need the heating funciton?

Iv heard that the BRZ limited seats are not direct fit. There will be sensor issue?