Fitting Heated Seats - a rough guide... [By GSB]

GSB · February 17, 2005, 19:41

After exchanging a couple of PM's with Darth Paul, who has already fitted these some time ago, I had a crack at it myself... I think its safe to say its not nearly as straightforward as it looks, so if you intend doing it yourself, leave yourself plenty of time and make sure you have the right tools and materials. For reference, the job took me just under 3 hours from start to finish, so if your unfamiliar with cars in general, and with upholstery and electrics specifically, allow yourself an easy day to do it so theres no mistakes.

Also note that this is not a definitive set of instructions, merely a rough guide to the way I installed the seat heaters, and I can take no responsibility whatsoever if you choose to copy me and screw up your interior. Also note that the photos below show the custom leather interiors fitted to mine and DP's cars, so there may be a few detail differences in leather seams, and fixing placement compared to the stock leather or cloth interiors. You'll also note that both Paul and I have more or less exactly the same interiors, which is neither a sign of copying, plagiarism, or lack of originality. It's merely a sign that we both have astoundingly good taste... s:wink: :wink: s:wink:

So, those of you who have bought the kits via Stevewarbs GB with Tem's contact with Toyota Finland will note that you have 4 rectanglar pads, a bunch of wires, and a couple of switches. So lets start by sorting out these bits and working out where they go. The pads come in pairs and have a couple of self adhesive strips to secure them inside the seat. You'll also notice that the pads can be split by unplugging them from each other. When unplugged you'll see that most of the wiring loom is left attached to one of the pads, this pad also contains the thermostat unit, which can be felt as a lump within the pad adjacent to where the wire joins to the pad. Dont worry, once its in place you wont be able to feel it.

The pad with the thermostat is fitted to the backrest, and the one with the shorter cables and the single plug at the end is fitted into the seat base. The location of the switches is entirely optional, but frankly the only obvious place is in the centre console, so thats where I put them.

Heres a rough guide to the location of the pads once installed:

So, grab yourself a ratchet and a 14mm socket, drop the roof and the windows, and whip the seats out. Not forgetting of course to unplug the electrical connections underneath... Oh, an d be very carful when pulling the seats out of the car, its very easy to scratch things.

Once out, you'll need a sturdy workbench, and some clean rags or similar to rest the seat on at all the peculiar angles required for this job. I started with the drivers side seat:

Next, you'll need a pair of sidecutters and small terminal screwdriver. remove the seatbelt sensor plug from the base of the seat, and cut the cable tie securing the wire to the springs. Next, you'll need to remove the height adjusting knob from the side of the seat. This is secured by a spring that you can push off with your terminal screwdriver, the picture below will show you what your dealing with here:

Next, take a 12mm socket and a ratchet, and remove the four bolts that secure the lower seat squab to the subframe. Once these are removed, you should be able to lift the squab from the rest of the seat, leaving it looking like this:

The leather on the seat base is secured at the rear by a long black plastic strip, this will need to be unhooked from the steel seat base to allow you access to pull the cable through:

The arrangment at the front of the seat base is similar, but using a similar hooked over plastic strip that goes across the front and part way around each side. Once unhooked, the front of the leather cover can be lifted, exposing the foam underneath: (Err... Sorry about the messy workbench!)

Next take the pad that does not have the thermostat inside, and feed the cable through from the front to the rear of the seat, along the side that runs next to the centre console. Small hands are good here, as you'll need to feel around for a way through, and pull the cable out from the rear of te seat squab. Once through, you can position the pad itself under the leather cover. The pad will end up in a postion where the cable entry is in the rear, with the adhesive strips against the foam base, like this:

Once in position, the pad will be up against the seam at the rear of the cavity (possibly just a custom leather thing) and the cables routed so you wont be able to feel them once the seat is back together. Once your confident that the pad is in the right placem remove the paper strips and stick the pad down to the foam:

Once its all together, refit the leather cover and hook everything back together underrneath. At the rear, make sure the cable emerges at the correct side before refixing the black plastic securing strip.

Next, we move onto the backrest. Place the bottom part of the seat squab to one side, and spin the main part of the seat over so its resting on the headrest and the front edge of the subframe. Heres where it gets interesting... The joint in the leather at the bottom of the backrest is "stitched" together using a legth of steel rod. This rod was bent over at both ends and is made of that really annoying material that is impossible to straighten... So, out with the bolt croppers to chop the end off, leaving plenty left over to thread it back in of course...

Once pulled out, the cavity for the heater pad is easiily accesible, so insert the pad as before, and stick it down to the foam. Now it gets ugly, threading the rod back in will be alot easier if you have a file or a grinder nearby to round of the end and stop it snagging as you push it though, and a damn site easier if you have an assistant with you. Of course, with persistance and a bit of time its do-able on your own. Once again, make sure the cable comes out of the correct side before re-assmbly.:

Once the 2 pads are in, then reassamble the seat, and connect the 2 pad cables together. Use cable ties to resucure the seatbelt sensor cable and the new heater cables to the springs, and dont forget to put the height adjuster knob back on. s:wink: :wink: s:wink:

Repeat the operation with the passenger seat... s:roll: :roll: s:roll:

Next, the switches and the wiring....

Unscrew the gearknob and the four cross-headed screws in the sides of the centre console. Lif the console up and turn it over and you'll be able to unplug the window switches and remove the console from the vehicle. Once out, apply a piece of masking tape, and then measure and mark up where you want the switches. Drill a small pilot hole, and then run a 20mm hole saw through the console at the 2 switch positions. The switches will then snap straight into the holes:

Now the wiring. Its pretty simple really, you need a 12 volt feed wire to the switches, and obviously you'll need a negative earth wire as well. The red cables on the pads need to connect to the centre terminal of the switch, and the black wires can be joined together and routed to earth for simplicity, or if you want the little red lights in the switches to work as well, you can wire the switches as shown below:

In the photo above, the red and grey wires heading off to the left are the main power feed, which will be connected to the power source in the car. The red positive wire goes to the + terminal of each switch while the grey wire is connected to the gold earth terminal of both switches (this connection makes the little red lights work) as well as to the negative return wires of both seat heaters. The centre terminals of the switches are in turn connected to the red wires of the seat heaters... You can see the pairs of wires for each seat heater heading off to the right in the photo above.

Once its all wired up, put the console back in the car, not forgetting to reconnect the window switches. Feed the 2 wires for your power feed under the carpet in front of the gear shifter. If you split the carpet open behind the ashtray (theres a velcro strip that holds the 2 halves together) you'll be able to feel for the cables and pull them through. Fully re-install the centre console leaving the 2 power feeds for your seats dropping out of the sides adjacent to the centre console cup holder. You can now install the seats, connecting your new power feeds to the seat heaters and not forgetting to plug the seatbelt sensors back in before bolting it all down. Dont forget to leave enough slack to allow the seats to move back and forth.

Once everything is together, you can connect the power supply. I used the cigar lighter supply, as its more than man enough for the job, is switched with the ignition system, thus eliminating flat batteries from leaving them switched on, and is very handily positioned. If you choose to use the same supply, then I think the pinky coloured cable on the back of the cigar lighter is the positive feed.

Thats it. Switch on and enjoy rosy cheeks!

Darth Paul · February 18, 2005, 00:16

Quote from: "GSB"Trust me, the wiring is the easy bit... s:shock: :shock: s:shock:

What he said! s:wink: :wink: s:wink:

Just be careful of the driver's seat height adjusting knob – the rear of mine smashed and I had to buy a new one for £10. s:? :? s:?

Anonymous · February 18, 2005, 19:51

Excellent article Grant, reminded me that I had still got to fit mine (as well as your bonnet struts and Markiis inlet pipe and sort out the donation to club funds from the GB and sort out why I have a lake in the passenger footwell of the Scorpio and why the heater in the Scorpio has packed up and finish the decorating, and, and, and.......)

Anyway, took the seats out when I got home from work (10 minutes) and I have finished one seat (just over 1 hour) and will have the other ready to go back in the car tomorrow morning (although I have mislaid the switches) but I have a couple of observations...

My car is a 2000 MY and the height adjuster is different to your picture, there is a clip the same but it is behind the wheel not in it as in your car, it's quite easy to get outby poking a screwdriver behingd the wheel, it just pings out. I bet getting it back in is going to be a pig though.

Also, when releasing the leather on the backrest on the 2000 MY there are 3 copper clips that I have cut through with the side cutters which releases the leather without the problems of threading the steel bar back through. I simply reconnected the leather with cable ties. Like Grant, though, I accept no responsibility s:roll: :roll: s:roll:

Darth Paul · February 19, 2005, 17:46

I just opened up the copper clips. I even re-used them. s:wink: :wink: s:wink:

markiii · April 3, 2005, 18:55

seeing as how the pics have dissapeared can someone confirm if the pads go in vertically or horizontally?

thanks.

GSB · April 3, 2005, 21:35

On the seat base the pad goes in so that wire comes out of the back, and on the seat back the pad goes in so that the wire come out of the bottom. You then route the cables over to the side nearest the centre console.

Anonymous · November 14, 2005, 09:27

I've got the standard leather seats that came with my 2001 and the seat back is different. It doesn't havethe copper rings and the wire rod it's got a zip that runs full width at the bottom, unfortunately the zip doesn't have the bit that slides. Both seats are the same, any tips?

Can anyone point me to a trimmer in the Wokingham/Reading area that I could get to do it?

Anonymous · May 9, 2006, 00:32

How did I miss this thread? I had to figure it out, too. All I did was slice away about 1/2 inch of foam from the bottom of the driver's seat to get a lower seating position. It took about an hour and a half. I would not recommend taking out any more than that, otherwise the leather won't hold its shape.

I'm thinking of taking it out again to figure out how to modify the seat so it is even lower. It didn't look too promising when I had it all apart before.

Anonymous · May 9, 2006, 01:16

beanie - thats exactly what i was thinking about doing to get a lower driving position

i have cloth seats so i'm thinknig i can take more off and still get the cloth relatively tight and not baggy

having said that i'm overseas right now and cant get to my 2 for a couple of weeks so i'll watch out for some posts/ideas from you

Anonymous · May 9, 2006, 02:44

My seat leather had some ripples in the side bolsters at first but they went away. I think if I had sliced any more off it would have been bad news. When my weight is in the seat it seems to be compressed more than the amount of foam removed. You get a little more side bolstering, which is nice. Not recommended for large backsides.

I used a large X-Acto knife (new and sharp) and shaved a small amount off over the whole bottom side, layer by layer, trying to avoid uneveness. It isn't that critical because the result was kind of bumpy (visually), but I can't feel any variation.

Like GSB said in so many words, it is tricky getting it apart and back together again due to several things, including the wires built into the foam and the rings that pull it all tight. This would make it tempting to try and take off as much as possible and avoid doing it twice, but my advice is to take off about 1/4 inch, see how that looks and feels, then repeat if necessary.

I don't think I'll be taking the seat apart again anytime soon because I have other projects to work on. I'm also thinking about Lotus Elise seats (eBay, salvage, or elisetalk). If they would fit, it would be worth having some custom rails made. Elise seats would be perfect -- nice appearance, light, thin, and supportive.

One last thing: Be careful with the seat adjusting knob. I broke mine. It is not very strong plastic. s:oops: :oops: s:oops:

roger · October 6, 2006, 12:42

Fitted mine a couple of weeks ago, can I add a word of warning to the Electrical installation side.

I drilled the holes for the switches and found one of them was right through a clip on the underside that holds the window wiring loom.

Since the console was off the car no electrical problems, but what it did do was "shake" the drill, leaving a not too perfect hole, so the switch isn't fitting as tightly as it should be. Also the connections to the switch foul the loom, when it all goes back together.

Bodged it around so its all not too bad, but highly recommend that you "look before you drill", something I didn't do s:oops: :oops: s:oops:

Thanks Tem & Grant for all your efforts, this and the GB.

By the way - the one mod Alison absolutely loves! Originally I thought having cloth seats didn't really require the heater, but she puts it on now, regardless of weather or temperature. s:D

s:D

markiii · October 6, 2006, 12:56

it's great for a long driveif yoru back aches as well :-) :-) :-)

roger · October 6, 2006, 13:52

Quote from: "markiii"it's great for a long driveif yoru back aches as well :-) :-) :-)

Yeh, she does actually suffer from a bad back, that's why. Unfortunately she gets more relief in the car than in the bedroom now....or perhaps I shouldn't say that, prepared to be Modded s:wink: :wink: s:wink:

celmacmat · October 6, 2006, 16:45

I have the loom, still I won't have a clue where to start s:? :? s:?

I would be more in my element doing an oil change, but electrics for me is a no no (I become a blonde when it comes to electrical ...sorry for the blondes it is not ment to offence s:wink: :wink: s:wink: ) so I unfortunatly need a sparx.

But I don't want to get riped off s:? :? s:?

roger · October 6, 2006, 17:14

Well assuming you can take out and put back the centre console and drill the switch holes your sparx will be with you for no longer than 10 minutes.

If he does that as well, and has to play it by ear because he doesn't know what he is doing, then add another 20 minutes.

Whether his charge will be a rip-off will be for you to decide, but 1/2 hour of a sparx + travelling, not much change from £45 (+VAT?) I would think. But any price is a good price if you are unwilling or unable to do it yourself.

celmacmat · October 7, 2006, 17:14

That is a good point Roger...I can;t do it myself so I will have to pay.

Cheers for the insight any way..

Tem · October 7, 2006, 19:34

Just to clear up the confusion about the wires. The first batch, which was mailed to UK in one box and then resend within UK, came without wires. Wiring and electrical stuff is easy for me, so I never even thought there would be interest for a loom, sorry about that. s:oops: :oops: s:oops: Grant/GSB made a wiring loom within UK for those who wanted and all the early ones have his loom.

After that each set was sent out when ordered and I sent few without any wires, like in the 1st GB. Then someone (sorry, I forgot who you were s:oops: :oops: s:oops: ) asked if I could make a wiring loom ready for him and that was the 1st one I did. He was happy with it and I added that as an option. So all looms coming within the package these days are done by me.

Never saw Grant's loom, but I assume both are more or less the same. There's not too many ways to connect these. s8)

s8)

Anonymous · October 18, 2006, 02:31

I've had my heated seats for nearly a year now -thanks Tem.

Just wondering - when I first turn the heated seat on after few minutes I get the lovely glowing warmth coming through the seat. This lasts about 5minutes after which the elements seem to switch off. I assume this is because the seat has "reached temperature" and a thermostat kicks in. The warm sensation then goes.

I just wish I could have that hot water bottle feeling permenantly as it's great if you have a sore back s:(

s:(

Tem · October 18, 2006, 04:52

Quote from: "simonp"I've had my heated seats for nearly a year now -thanks Tem.

Just wondering - when I first turn the heated seat on after few minutes I get the lovely glowing warmth coming through the seat. This lasts about 5minutes after which the elements seem to switch off. I assume this is because the seat has "reached temperature" and a thermostat kicks in. The warm sensation then goes.

I just wish I could have that hot water bottle feeling permenantly as it's great if you have a sore back s:( s:(

Yes, it's the thermostat kicking in. s8)

s8)

Someone took the thermostat off, cause he wanted it hot too. Sorry, I forgot who you were, please post the details if you're still around. s:oops: :oops: s:oops: We talked about it through PM, but I don't seem to have them anymore.

It's the "lump" within the other element. IIRC, he used a knife to cut through the foam and then just solder the wires going into the thermostat together, leaving the thermostat there, just unconnected. He did say that it gets VERY hot without it though and he has to control them manually with the switch. He planned on installing a thermostat for higher temp, but I'm not sure if he ever got to it.

I wonder how those switches with multiple settings work and if they could be used here...anyone familiar with them?

celmacmat · October 18, 2006, 10:08

Got the seat connected by the Sparx s:D

s:D

Everything is working, little lights on switches and all...

However, glad i ask a Sparx to do it, the loom was wired the wrong way round e.g. all positive wires were where the negative should have been and vice versa s:? :? s:?

But it works now and i have a warm bum s:wink: :wink: s:wink:

philster_d · October 18, 2006, 10:39

maybe you could replace it with a variable resistor

Anonymous · October 18, 2006, 11:43

cheers,

As long as it's not just mine playing up.
DOn't really fancy ripping the pads out now they are in to take them apart.

Re the multi switches - this kit has them

http://www.carfi.co.uk/html/heated_seats.html?gclid=COT1kKG4gogCFTdoEQodf36lHA

(btw - over £300 more than it cost to fit mine!!!!)

But I think you need some form of additonal control module.

Tem · October 18, 2006, 11:54

Quote from: "celmacmat"However, glad i ask a Sparx to do it, the loom was wired the wrong way round e.g. all positive wires were where the negative should have been and vice versa s:? :? s:?

I'm really sorry about that! s:oops: :oops: s:oops: I have one example loom at home, which I use to make them, so I can't understand how I've made a mistake like that.

Has everyone elses been ok? s:? :? s:?

davidhowson · October 18, 2006, 14:54

I finally got round to fitting my seat heaters last weekend, and they work a treat. I actually made my own wiring loom and bought the Toyota heated seat switches which fitted nicely into the blanks on the dash to the left of the steering column. These switches have a high and low position, but so far I have only connected the high setting. I think I may have a go at a low setting using resistors to see if that creates a "simmer" setting rather than the "boil". However, I may need to tamper with the termostat to achieve this and I'm not sure I want to do that.
I can recomend the Toyota switches as they fit and look like "standard" kit. David

celmacmat · October 18, 2006, 16:39

Quote from: "Tem"
Quote from: "celmacmat"However, glad i ask a Sparx to do it, the loom was wired the wrong way round e.g. all positive wires were where the negative should have been and vice versa s:? :? s:?

I'm really sorry about that! s:oops: :oops: s:oops: I have one example loom at home, which I use to make them, so I can't understand how I've made a mistake like that.

Has everyone elses been ok? s:? :? s:?

No worries Tem, i couldn't have fitted them myself anyway...and this is what the guy said which might be not true s:wink: :wink: s:wink: