Easy DIY Seat Warmers/Heaters with $45 eBay kit

Lately it's been below freezing when I drive to work in the morning, and I found myself wishing for seat warmers like those that I've experienced in friends' and family members' newer cars. I did some YouTube research on installing aftermarket seat warmers, but all of those videos included removing the seats, taking apart the upholstery, attaching the warming pads, reattaching the upholstery with special hog ring pliers and then putting the seats back in. Here on TW I read about people getting seat warmers as an add-on to their Wet Okole seat covers. I already had some cheap neoprene seat covers, so I figured I could just buy an aftermarket carbon fiber seat warmer kit and attach it directly on top of my upholstery, and then put the seat covers back on over them. Most of the kits I found on Amazon and eBay came with two crappy looking circular switches with only Off/Low/High on them, and they would require drilling holes for placement. I found one kit for $45.88 on eBay that came with four carbon fiber & fabric seat pads, and a great wiring harness that included one rectangular switch to control both seats with 0-5 heat level settings. The switch fit perfectly into one of the pop-out switch holes next to the 12v plugs below the ashtray & stereo in my 2004 Tacoma. The L & R and seat warmer image on the switch are backlit blue, and the numbers on the level dials light up red when on.

Here is a link to that kit: https://www.ebay.com/itm/393420644922 And the long eBay name of the kit is:
"12V Universal Car Carbon Fiber Heated Seat Heater Kit Cushion 5 Position Switch" sold by jwtek

From the eBay listing:


Quick and easy pop-in switch placement in the blank spot next to the 12v outlets. The LED light bar rocker switch was much harder to put in, and required grinding away plastic with a dremel to make it fit.



The above photo is from the eBay listing and doesn't show the included relay that is after the gold colored box (switch box? regulator?).

I don't have photos of the wiring process and layout because I did that part in the dark, but it was quite easy to hard wire with the included wiring harness. I zip-tied the relay and switch box in an empty area behind the 12v plugs and switch. I then butt-spliced all of the positive wires to one longer wire that was spliced to a micro add-a-fuse going into a fuse slot in the cab fuse box. The fuse slot I chose only allows the seats heater to come on when the key is in the ignition, so won't drain the battery. The way I wired it has the switch back light always on when the key is in the ignition, but it could be wired separately from the other positive wires so that it only comes on when your DRLs and/or headlights are on. This wasn't important to me because I always drive with my DRLs on.

The negative wire I extended and attached to a bolt going into the body of the truck. For the wires that ran from the switch to the heat pads I removed the center console and ran them underneath the gear shifter housing and the center console area and then off to each side under the seats. This involved many zip-ties to keep the wires in place and prevent them from getting caught in the seat rails when moving the seat forward or back. These wires had quick connects on them that were connected underneath the seat to the quick connect wires coming off of the pads through the crack in the seat between the top and bottom.

To attach the heat pads to my seats I simply vacuumed the seats, found the best placement, and then removed the backing from the attached adhesive. I also used fabric wire harness tape along all of the edges of the pads to further prevent them from moving. Once the pads were in place and the wires all hooked up and out of the way I put the seat covers on and the warming pads were completely hidden and unnoticeable except when turned on. They are also easily removed without any damage to the seats.

I used the seat warmer for the first time to drive to a friends' house for a Thanksgiving dinner potluck and used the passenger seat warmer to keep my sweet potato dish warm. The seats got hot within a few minutes on the 5 setting, and within 20 minutes I had to turn them down from 5 to 2 because my butt was getting too hot.
In the future I'd like to get some better fitting and higher quality seat covers, either the Carhartt or Durafit ones. Wet Okoles look great, but are out of my price range.

Let me know if you have any questions. I hope this inspires others who want seat warmers, but don't want to remove and disassemble their seats to do so.

 

After having heated seats in my newer vehicles I definitely wouldn’t mind having them in my Toyota, great idea!

 

Thanks! It sure makes a huge difference in comfort on those cold mornings, or after going snowboarding or skiing.

 

I'm going to give this a try for sure. My girlfriend has heated seats in her Jeep and I've got to admit it's pretty nice.
Edit: Just ordered. Thanks for the link!

 

You're welcome! Let me know how the install goes. Do you already have seat covers?

 

Definitely doing this

 

Yes, I've got carhartt seat covers up front. Haven't picked up a set for the rear seats yet. They're kinda spendy!

 

Pretty easy to pull the oem seat covers off. Just need some hog ring pliers and Rings to put back together. I used a similar kit to this last year and have loved it.

 

Any chance these could do any damage if you put them on top of the oem fabric? I can't imagine they would get hot enough, but now I'm wondering.

 

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I don't think the adhesive is strong enough to permanently bond with and damage the oem fabric.

 

Kind of curious why you used the fabric tape along the sides. Is it just to keep it from peeling up?

 

Yes, I was worried about the pad shifting and I wanted to smooth out the edge of the pad to make it harder to see or feel through the seat cover. Works so far!

 

Great to know these products exist! but... what on them is actually carbon fiber?

 

I just learned about this too. The heating element / wires in the fabric are comprised of carbon fiber coated in copper or nickel.
https://www.azom.com/article.aspx?ArticleID=1624

 

Thanks for the link. I had incorrectly assumed the ebay seller was just trying to use click words...

 

One thing I miss about this old 740 Volvo I had. Heated seats and you are spot on about after snowboarding. Dried you off and kept ya toasty!

 

Here are my new Durafit Leatherette seat covers over the heating pads. The seat covers fit quite nice and have back and side pockets. They were $129 off the Durafit website, which is much cheaper than Wet Okole covers, and easier to clean by wiping them down. https://durafitseatcovers.com/T782/