DIY: Heated child car seat

[SubOperator]

Disclaimer: This thread describes some modifications performed to car child seat. While no changes have been made to design of the seat and no components of child seat or restraining system were modified in any way, I am not to be held legally liable for any consequences of someone repeating steps shown here in any way, or using them as aspiration to perform similar or identical modification to any other child car seat.

 

Now with legal stuff out of the way:

 

My LGT is parked outside year long. Wanted to do something to make my daughter feel comfortable getting in the car in the winter other than idling car for 10 minutes. Also wanted to have same ability for my wife’s car when they drive to after school activities and her Tribeca sits outside in the winter.

 

I figured I wanted to have something I can move in and out of the car (cleaning, day care trips, etc) so I didn’t want to have it permanently wired. I also wanted my daughter to be able to control it so it had to be easy to operate (turn on/off) and ideally have more than one level of heat.

 

Obviously it had to be safe, both mechanically and electrically, so having a fuse was a must.

 

So with that I went online and gathered some parts. Note that since I am writing this long past actual work was done, I looked on Amazon again and found similar, and in some cases better parts than the ones I have in photos here.

 

 

I wanted to have two child car seats converted (my LGT and wife’s Tribeca B9), so I found “Tech Era Carbon Fiber Seat Heater Kit Hi/Lo Setting, 2 Seats ”, current price $42.99 Prime. The set contains heating pads for bottom and back foe each set for 2 seats, wiring harnesses, with relays and 2-stage control switch with LED indication and even protective fuse. Important detail here is that the bottom and back heat pads are separate pieces that can be connected to wiring harnesses individually.

 

https://www.amazon.com/dp/B008D2LIRG/ref=psdc_15736761_t1_B00AKEVNP2

 

 

http://legacygt.com/forums/attachment.php?attachmentid=260498&stc=1&d=1515553927

 

 

Next I got cigarrete lighter socket connector with tail, with built-in power LED and fuse. Now, in my project I got one with short tail and extended it with extra power cable. What I found on Amazon though is a much better option imo, its and extension cable with 2 connectors, each with LED and fuse, on 10 ft power cable. You can cut it in half and have a ready made 5 ft cable with power connector foe 2 car seats. Price is pretty much the same.

 

“LST 12V 15A 10FT Heavy Duty Male to Male Cigarette Lighter Plug Charger Cord With LED Lights And Fuse Protection On Both Plugs ”, $9.55 Prime.

 

https://www.amazon.com/dp/B073ZZWHSC/ref=sspa_dk_detail_6?psc=1&pd_rd_i=B073ZZWHSC&pd_rd_wg=j66cd&pd_rd_r=HJ5PCVHPBYMGXHKDSJEK&pd_rd_w=3vUMd

 

 

http://legacygt.com/forums/attachment.php?attachmentid=260499&stc=1&d=1515553927

Edited January 10, 2018 by SubOperator
added legal disclaimer.

[SubOperator]

I wanted to protect all wiring with some flex split tubing so got ½ or 3/8 inch tubing, make sure you get enough for power cable and control switch cord. This is one to look at, “3/8" Flame Retardant Polypropylene Split Wire Loom Tubing - 25 Feet – Black”, $13.95 Prime for 25 feet:

 

 

https://www.amazon.com/Flame-Retardant-Polypropylene-Split-Tubing/dp/B01N677VYC/ref=sr_1_8?s=automotive&ie=UTF8&qid=1515473078&sr=1-8&keywords=wire+conduit+flex+split

 

 

http://legacygt.com/forums/attachment.php?attachmentid=260500&stc=1&d=1515554404

 

 

Aside from above, you’ll need some zip ties, electrical tape and/or some heat shrink tube (1 inch and 3/8), and (optional) some duct tape and similar tape to affix heating pad to seat’s frame. All of that is available on Amazon, I happened to have all of that already. Heated pads set includes some sticky pads already thats why duct tape is optional.

 

 

So the idea here is that the heating pad from the heated seats set need to be placed under the cloth cover of child car seat, affixed to the plastic frame such that it stays in place, and have wiring connected to deliver power to heating pad and provide on/off and heat level control to your precious passenger’s comfort.

 

First order of business is to get the seat disassembled enough to have seat cover off. I am using our Recaro seat in this example, and while every seat will be different to some extent, hopefully they are close enough in design.

 

Here is the fully assembled seat, with all the heating pad and wiring already installed.

 

FRONT:

 

http://legacygt.com/forums/attachment.php?attachmentid=260501&stc=1&d=1515554404

 

SIDE:

 

http://legacygt.com/forums/attachment.php?attachmentid=260502&stc=1&d=1515554404

 

REAR:

 

http://legacygt.com/forums/attachment.php?attachmentid=260503&stc=1&d=1515554404

 

Note that when not in use, the power wire and control switch cable are coiled and neatly packed under and behind, out of the way.

 

Our Recaro has height adjustable back, so the first thing is to remove it. There are 4 bolts and nuts that need to be removed first. Here are bolts in the back:

 

http://legacygt.com/forums/attachment.php?attachmentid=260504&stc=1&d=1515554404

 

Also seen in the pic is how the wiring is secured to frame with zip ties. I didn’t want to drill any holes or make any cuts in the seat frame to keep its structural integrity.

 

http://legacygt.com/forums/attachment.php?attachmentid=260505&stc=1&d=1515554404

Edited January 10, 2018 by SubOperator

[SubOperator]

The bolts heads can be accessed from front, on Recaro its T3 socket (small)

 

http://legacygt.com/forums/attachment.php?attachmentid=260506&stc=1&d=1515555484

 

The other side:

 

http://legacygt.com/forums/attachment.php?attachmentid=260507&stc=1&d=1515555484

 

The height adjustable pad is off, now you can see the upper part of heated pad (white) behind seat cover:

 

http://legacygt.com/forums/attachment.php?attachmentid=260508&stc=1&d=1515555484

 

After seat cover is removed, you should be able to get to seat frame. Do not cut/drill it to attach heating pad. I used drywall sticky tape, you can use the sticky pads included in the set:

 

http://legacygt.com/forums/attachment.php?attachmentid=260509&stc=1&d=1515555484

 

One pad is usually enough, I do not think it matters whether you choose back or bottom part, but make sure the size is proper for your car seat. Other than connecting power cable tail, everything else should connect using included harnesses with connectors, so no soldering beyond power cable tail is required. Here are second halves with harnesses that I didn’t use for this project:

 

http://legacygt.com/forums/attachment.php?attachmentid=260510&stc=1&d=1515555484

 

Finished install , note the power cable running to top and then to the back behind the seat in upper left corner:

 

http://legacygt.com/forums/attachment.php?attachmentid=260511&stc=1&d=1515555484

 

 

I used heat shrink tubing to protect all connectors, you can use that or electrical tape:

 

http://legacygt.com/forums/attachment.php?attachmentid=260512&stc=1&d=1515555484

 

Put all wiring in protective split flex tubing, here is back of the seat with harnesses for power and control on different sides, relay fixed in position with zip ties. When using zip ties, make sure there is no blockage or restriction to movements of child car seat:

 

http://legacygt.com/forums/attachment.php?attachmentid=260513&stc=1&d=1515555484

 

 

Here is the cigarette lighter socket connector:

 

http://legacygt.com/forums/attachment.php?attachmentid=260514&stc=1&d=1515555484

 

Both power connector and 2 stage heater on/off switch (medium position is off).

 

http://legacygt.com/forums/attachment.php?attachmentid=260515&stc=1&d=1515555484

Edited January 10, 2018 by SubOperator

[SubOperator]

The heating pad harness contains the relay for controlling 2 stages if heat, I connected it to harness and power cable per diagram in the set, and secured it with zip ties:

 

http://legacygt.com/forums/attachment.php?attachmentid=260516&stc=1&d=1515556288

 

The switch after being put in flex split tubing and fixed in place with shrink tubing (tape can be used instead)”

 

http://legacygt.com/forums/attachment.php?attachmentid=260517&stc=1&d=1515556288

 

http://legacygt.com/forums/attachment.php?attachmentid=260518&stc=1&d=1515556288

 

Power connector with LED and fuse. LED is really useful actually as you instantly know if its plugged in or not:

 

http://legacygt.com/forums/attachment.php?attachmentid=260519&stc=1&d=1515556288

 

 

As I stated prior, I wanted to be able to move the seat inside the car, place it on either side of rear seat. Also, the LGT has cigarette socket in compartment between front seats while Tribeca has one on left side by 3 rd row. SO I wanted the power cable to be long enough to reach either socket. I believe I left power cable at 5 feet; it works great in both vehicles.

 

 

http://legacygt.com/forums/attachment.php?attachmentid=260520&stc=1&d=1515556288

 

That's all for the heated child car seat part.

 

Now, if you have gotten to this point here is a bonus. With any child seat its hard to reach for seat belt locks, and Recaro seat is MASSIVE, which makes buckling up especially challenging.

 

I found these seat belt extenders on Amazon, I don’t have a link at the moment. They say FORD on them but worked like charm for all our Subarus. One thing to know though is that these are for side seat belt buckles:

 

http://legacygt.com/forums/attachment.php?attachmentid=260521&stc=1&d=1515556288

 

http://legacygt.com/forums/attachment.php?attachmentid=260522&stc=1&d=1515556288

 

http://legacygt.com/forums/attachment.php?attachmentid=260523&stc=1&d=1515556288

 

 

 

Hope this helps!

Edited January 10, 2018 by SubOperator

[Dishwasher]

This is so awesome. I'm doing it.

[SubOperator]

This is so awesome. I'm doing it.

 

Yes once you have it you will appreciate it (and so will your child ). Quite frankly Idk why companies that make child seats and boosters don't offer that as an option. Modern car seats run ~$200 easily, I'd pay another $50 to have it from factory properly integrated.

[fedaykin]

"No market/buyers, no care."

You probably just created a market for them, well done.

[covertrussian]

I gotta say this is awesome!

 

Are they water proof? Lets just say my kid likes to have accidents or spill water...

[SubOperator]

Are they water proof? Lets just say my kid likes to have accidents or spill water...

 

I believe they are to a reasonable level. I didn't fully submerge them in water of course, but had plenty of "accidents" and water/juice spills , snow melting, few times forcing me to disassemble the seat to put the covers through washing machine.

 

Didn't have any problems with liquids.

[teezythakidd]

this is so legit. needs to be in a manual somewhere! im adding this to my projects to do pre-winter this year!