Aftermarket Heated Seats

[bigdaddylee82]

So I put it off, and put it off, but I finally did it. It's been about 6 years since my power drivers seat has been able to recline, thankfully it failed in my normal comfortable driver position. Well now the seat reclines and it keeps my buns nice and toasty. I don't handle the cold well, and this is our second Ohio Winter. After last year I swore I'd have remote start and heated seats before I went through another Ice Age. I got the remote start done back in Nov. but I really dreaded the upholstery work involved with the seats, turns out it wasn't that bad. I killed two birds with one stone, so to speak, doing the heated seat upgrade at the same time as fixing the recline cable.

There's no need to reinvent the wheel, the seat cable repair/replacement has been covered well in the forums. I found this one to be the most helpful in removing the back upholstery:
volvospeed.com/vs_forum/topic/143835-write-up-850-seat-back-cable-replacement/

Instead of replacing the cable that operates the power recline I used the heat-and-press repair as seen here:
volvoforums.com/forum/volvo-850-16/850-seat-back-cable-repair-16364/

"fixed" motor side:

Motor Cable.JPG (153.09 KiB) Viewed 9192 times

"fixed" transmission side:

Transmission Cable.JPG (177.18 KiB) Viewed 9192 times

The Aluminum foil was a heat shield to keep me from setting the seat ablaze with my propane torch.

Enough about the seat repair, on to the heated seat. I bought a Dorman 628-040 Universal Seat Heater Kit from Amazon.com, and installed it after repairing the seat recline cable. The kit comes with 2 heating elements, one for the seat back and one for the seat bottom, a 3 way rocker switch, wiring harness with pre-wired relay and fuse. The kit also comes with the cheapest piece of junk hog ring pliers, and what they call "hog rings" certainly aren't like any I've ever used. The pliers broke on the second "hog ring" I attempted to use, so I pulled out the zip-tie kit and improvised.

Dorman Kit:

Heated Seat Kit.JPG (117.99 KiB) Viewed 9192 times

So if you've repaired the recline cable, then putting the back heating element on is all gravy, there's adhesive on the edges of the heating element, simply peel and stick, making sure your wires are ran so that you won't feel them and they won't bind on anything during normal seat operation.

If you can remove the seat back upholstery then you can do the seat bottom too. There are 3 hog rings along the edges of both sides of the seat, and 4 hog rings along the back of the seat that all need to be cut. There's also 2 sneaky hog rings on long strips of upholstery attached to the the outer most springs on the bottom rear of the seat bottom, don't miss them or you'll probably tear the upholstery when trying to remove it. Also just like the seat back, there are hog rings under the upholstery, attaching it to wire embedded into the foam of the seat bottom. I only had to remove 4 of the hog rings under the upholstery to get it to fold back far enough to stick the heating pad in place. Same goes for the seat bottom as the back, mind your wire routing.

Heat Pads Instalaled.JPG (117.15 KiB) Viewed 9192 times

Now my car didn't come equipped with heated seats, however under the blanks for where the switches for heated seats would have been were it so equipped, resided the wiring harness ready and waiting for me to install my new-to-me eBay sourced Volvo 850 seat heater switches.

Please excuse the grossness of the car, when removing the seat from the car foam and 18 years of nasty kind of got everywhere. The flash of the camera really shows off just how dirty it is.

Blank & Switch Harness.JPG (175.65 KiB) Viewed 9192 times

Switch Installed.JPG (177.97 KiB) Viewed 9192 times

Guess what, not only does the heated seat wiring harness exist for the factory switch, so does the terminated end under the seat. This is the harness for the seat-belt reminder and heated seat, of course.

Wiring Harness Multimeter.JPG (172.73 KiB) Viewed 9192 times

So instead of using the switch and relay provided with the Dorman kit, I modified it to make use of the factory wiring harness and switch. The 3 way switch provide with the kit has a hi-off-low, however high simply turns on both heating elements, and low only turns on one, I didn't see a point in utilizing this feature. I have it wired so that the factory switch turns on both heating elements.

So Yellow/Red is the switched +12V from the factory seat heater switch, and Black is ground.

Modified Wiring.JPG (155.32 KiB) Viewed 9192 times

And there you have it, a seat that reclines again, and keeps your buns warm and toasty!

- Lee

[burnout8488]

Awesome writeup and great job! I love the factory integration, can't beat that.

I usually shudder when I hear "aftermarket heated seat" because it usually involves a horrific looking switch, but you did it all right.

What did the Dorman kit set you back?

[precopster]

Best non-genuine write-up I've seen!!

Can anyone tell me where the seat heater switches should be in a V70/S70?

[burnout8488]

Here:

[bigdaddylee82]

Awesome writeup and great job! I love the factory integration, can't beat that.

I usually shudder when I hear "aftermarket heated seat" because it usually involves a horrific looking switch, but you did it all right.

What did the Dorman kit set you back?

Thanks! I agree, the switch that comes with the kit is pretty generic, and would be out of place just about anywhere you put it. At work (Service Writer for Nissan dealer) the sales department had aftermarket seat heaters put in a '12 Armada that they sold claiming it had heated seats, but it actually didn't. When it came back from the car audio/accessory place that did the install, I opened the driver door, and there the el-cheap-o rocker switch was, mounted to the side of the plastic trim on the seat bottom, staring you in the face. So tacky, and out of place, my eyes went right to it every time I opened the door, but the customer didn't seem to mind.

It's this kit from Amazon: Dorman 628-040 It was $60-ish when I got it. Amazon's customer service was great, I emailed and asked if I could get a new set of hog ring pliers, but they couldn't get me just the pliers. They wanted to send me a whole new kit, but I already had everything installed, so instead they gave me a 20% credit back on the Amazon gift card I used to purchase them with.

Best non-genuine write-up I've seen!!

Thanks!

- Lee

[Wiggi]

A question on DIY heated seat repair, If I installed one of these after market elements into the seat, could it be connected directly to the existing Volvo wiring loom at the seat connectors? Would the canbus reject the the new values (assuming the canbus controls the seats)?

[JRL]

Canbus controls the P2 and newer seat heaters so you can't use the stock switches with the newer (01 -current) cars

[beigg]

How about for the pass side? I have no connector for the pass side at all for the switch. Where would that plug end be hiding? I pulled the complete center console and didnt see it. IIRC, the Black wire and then theres a wire with a brown stripe (I forget the color) is for the ps seat, that I know of. I traced it, but dont see where it ends at??

[bigdaddylee82]

I still haven't done the P/S. We moved back to a warmer climate, and 99% of the time I'm the driver of the car, of that time I very very rarely have a passenger with me, so I haven't bothered.

I'll try and remember to take a look though. For the D/S, I pulled the blanking plate for the switch out of the console and the terminated wire for the switch was right there. Same goes for underneath the D/S seat, terminated seat warmer wiring harness was already there.

I have not looked on the P/S, but I never expected it to be any different.

You don't have the wiring for seat heaters for either side? Is there a spot on the center console where the switches would be if the car had originally come equipped with them? Reference the picture of the switches earlier in this post.

- Lee

[beigg]

Only had the wiring for the driver side in place. If ya could look that'd be awesome. Been putting off getting back around to the ps heater wiring. ugh lol