The Subaru BRZ Limited comes with many more options than the Premium model – fog lights, a spoiler, push button start, automatic climate control, leather heated seats, and more. Out of everything additional the Limited offers, the only thing I really wanted was the heated seats. They weren’t worth the extra $2,000 over the less equipped Premium model to me, so I got the cheap seats (and car). The BRZ takes quite a while to heat up when it’s cold, and I appreciate the heated seats in my fiancee’s Ford Flex. Justin Abide’s Honda Insight also had them, but not from the factory – he installed them himself from a kit he bought on Amazon. For just $49.99, I could add butt warmers to my BRZ. So I bought them.
The kit consists of four identical heating pads for a pair of seat backs and bottoms. These slide between the seat upholstery and the padding underneath. They can be shortened and trimmed slightly narrower if necessary. (No modification was required for my BRZ’s seats.) The wiring harnesses are already complete with a fuse, relay, and two-way switch for each seat. In theory, you just plug everything in and connect your ground and power source – preferably one that is only on when the ignition is on so you don’t drain your battery. The beauty of this kit is that it’s generic. You can add heated seats to ANY car. Fabric, leather, or vinyl, bucket or bench, it doesn’t matter – it works with all of them. I’d add them to my beater Focus if I still had it. I may even add them to Project MJ once more important issues are fixed, such as firing on all cylinders.
The product description says “IT IS FOR SOMEONE WITH ADVANCED INSTALLATION SKILLS!” Yes, caps and all. Despite the big scary message, I decided to try it myself. I’ve previously performed a foamectomy on my first Miata’s seats to get my head below the roll bar, so I already know how to wrestle with hog rings and upholstery. That, plus a little wiring – how hard could it be?
Four Torx head bolts attach the seat to the car. I removed these, unplugged the seat belt and airbag sensors, and pulled the seat out of the car. A row of five hog rings pulls the seat back and bottom upholstery together.
Removing them gave me full access to the seat back, where I shoved in the heating pad. There are two contours in the seat bottom, each held down to a cross wire by two hog rings. I removed these and didn’t replace them, since doing so would have to go through the heating pad. Theoretically, I could’ve cut slits in the pad and put them back in, but that seemed like too much work, and the seats have retained their contours without them. To install the heating element I just pulled up the front edge of the upholstery and slid the pad in from front to back. There are adhesive strips on the bottom of the pads to help hold them in place, but it’s such a tight fit between my foam and upholstery that I didn’t bother using them.
My passenger seat has a sensor that detects the weight of an occupant to enable or disable the passenger air bags automatically. I put the heating element right on top of this sensor and it still detects correctly. Then I pulled all of the upholstery back to where it’s supposed to be, and replaced the hog rings with zip ties for simplicity.
The BRZ already has fuses for heated seats, one for each side, even though they aren’t used in my lesser equipped Premium model. I cut off the in-line fuses conveniently included at the end of each power wire, replaced them with fused taps for the ATM low profile fuses the BRZ uses, and plugged them into the factory heated seat fuse locations. I can’t put the fuse box cover back on because the taps stick out too far, so I’m keeping it in the glove box for the diagram of what fuse does what. I crimped ring connectors onto the ground wires and used the bolt for the fuse box itself as a ground.
I removed the center console to mount the included switches in the stock location, in a blank panel ahead of the cupholders and behind the shifter and traction control buttons. To my surprise, this panel is an integrated part of the center console rather than a separate blank panel snapped into place. There were markings on the underside for where to drill holes for the stock heated seat controls, so I drilled those out for my aftermarket switches. Someone who didn’t know better would think it’s a factory setup, it looks so good.
I zip-tied the wiring harnesses out of the way under the dashboard and ran them under the center console, since I’d removed it anyway. From there it’s a simple matter of just plugging the switches and seats into the appropriate plugs. The passenger seat worked perfectly on the first try. The driver’s seat didn’t. There was a bad connection somewhere that only allowed it to run intermittently on low power, and blew fuses on high power. Plugging the driver’s seat into the passenger side harness worked, narrowing the issue to the driver’s side harness and enabling the heated driver’s seat until I could pick up more fuses to finish troubleshooting the harness.
The other Justin offered to help me troubleshoot the problem, so we spent an afternoon blowing fuses. We tracked down and fixed a bad ground wire junction in the wiring harness, which made it stop blowing fuses. Then, no less than two or three times, I’d get the fully functional harness reinstalled, zip-tied out of the way, and was about to bolt the center console back in only to test it “one last time” and find that the circuit didn’t work anymore. We tracked down and fixed a couple more bad connections in the wiring harness and even replaced the relay socket, but to no avail. I ended up replacing all of the wiring with a harness of my own design, rather than continue wasting time chasing down issues in the existing one. This is definitely a case of getting what you pay for. It’s inexpensive, but it’s also cheap, especially in the quality control department.
At first, using a highly sophisticated scientific measuring device known as “my butt,” I didn’t notice the seats getting that hot, even on high power. But after a few hours of use they started getting downright toasty. On a cold winter morning I find myself using high power to warm it up quickly, then switching to low power. It’s good to have that extra power in reserve for the particularly cold mornings we haven’t had very many of this winter. I find myself getting comfortable in the car significantly earlier in my commute than usual, despite the engine and heater not warming up any faster. Since the BRZ doesn’t warm up very quickly, that’s exactly what I wanted from this kit. Sometimes I don’t even need to blast the heat for a few minutes once it’s finally available to warm up the cabin like I used to.
There may be better aftermarket heated seats out there. I would have second thoughts about buying this exact kit again. The wiring going bad seems to be a fairly common complaint in the Amazon customer reviews, as well as the reportedly non-existent warranty service. I fixed it myself rather than use the warranty, so I can’t comment on this from my own experience. But most people aren’t handy enough to whip up their own replacement wiring using the original one as a template like I did, so this is a pretty big concern, and most of the reason for my fairly low rating despite my raves. But for about $50 and a bit of work rather than a $2,000 option package, they’re still worth every penny to me.
(Top photo credit: Allison Feldhusen. All other photos by the author.)
The paragon of unrnestandidg these issues is right here!
Hi, did you ever have any issues with the passenger seat occupancy sensor? I have a kit to install heaters in my 2017 WRX base and I am worried about the passenger seat. Thanks.
I was wondering if you did anything special to the passenger airbag sensor. Have you noticed it having any issues after installing the seat heaters?