Prewired for Heated Seats?

[l008com]

Back when I was in S10 land, everyone knew that you could just toss on a steering wheel that had radio controls, because the trucks came prewired for this once it became an available feature (1999 I think). I'm wondering if this is the same case for heated seats in a trailblazer?
My truck is nice but its seats are SO cold. I'm tempted to try to install a pair in the front myself. I'll be much more likely to give it a try if the wiring is already there ready to go, and so all I have to do is install new switch panels in the doors, and install the actual heating elements in the seats.

 

[djthumper]

IIRC all of the wiring should be there for heated seats.

 

[Bill Reid]

What year is your Trailblazer? From what I've seen (up to 2005) at the junkyard its hit/miss based on year and as-equipped options.

Wiring for power and/or heated/memory seats is not necessarily provided depending on year. My 2003 LS does not support heated (or power) seats from what I've seen in any of its existing wiring harnesses.

Heating elements are glued to the foam... best bet is to try and get the foam with heat option only or buy the entire seat and swap your covers.

I'll speak to 2003 (not including seat air bag wiring)... and to my knowledge you couldn't get heated and/or memory seats without power seats and lets not forget about the driver and passenger seat (lumbar low current only) modules/seat harness that manage all of this.

You will need to find schematics for your year Trailblazer and compare what is coming out of the carpet and what is going into the door modules before you can determine if your Trailblazer is "pre-wired"...

Here is the schematics from 03 as a reference...

 

[l008com]

Well, I can tell you that I have a 2008 LT, which has factory leather and definitely had heated seats as an option. I can also tell you that I don't know how to read those wiring diagrams so even if I knew where to find some for my truck, they wouldn't be very helpful :/

 

[Bill Reid]

Unfortunately, I do not have schematics for 2008... my info only goes to 2005. I wouldn't know what/if anything changed from 2005 to 2008. If someone has power/memory/heated schematics for 2008 that could post them up then, assuming you already have power seats, we could tell you what wiring to look for in the harness coming out of the carpet under your seats / going to the controller in each front door...
If its there then it confirms it might be plug-n-play for you...

 

[l008com]

I will be VERY happy if it is. I'm always cold in general and when it's 0° out, it takes forever for these icy leather seats to warm up.

 

[TollKeeper]

Even if not pre wired you can get a universal kit. Pretty easy to install, and you can pick where you want the switch at.

 

[DAlastDON]

If it is completely pre-wired then your also going to need a memory seat control module in addition to both the door modules. I would just put in an aftermarket kit with their own controls.

 

[l008com]

This is an old thread but it's getting pretty cold out, so I've been thinking about doing this again. It sounds like the aftermarket kit is easier to install, but I like the idea of preserving factory buttons (that I'd have to acquire), vs having ugly 3rd party switches somewhere in my truck.

I'm also curious, just how easy or hard is it to take apart a seat then put it back together with the heating element? It seems like something that would be very difficult.

 

[TollKeeper]

I've taken the drivers seat on my envoy 2 times in the last year. it's not terribly difficult. I replaced the heated seat element in about 2 hours. that's from disconnecting the battery (air bag), complete disassembly, and reassembly.

I would continue to recommend the aftermarket heaters. you can put the switch right next to your power seat controls , and will hardly notice.

But replacing the door controller, plus the computer under the seat (don't remember the name of it) then taking it to the dealer to get it programed. .. It will get expensive.

 

[l008com]

I don't suppose there's a video how-to specifically for trailblazers? I saw lots of general how-tos on youtube but I'd like to get as specific as possible to avoid surprises. I've never done anything like this.

Also I know google will find me a million different seat kits but are there any that are "quality" vs "crap" kits? I won't ever want to do this again, I'll want the elements to last.

At this point I am leaning towards aftermarket.

 

[Reprise]

Also I know google will find me a million different seat kits but are there any that are "quality" vs "crap" kits? I won't ever want to do this again, I'll want the elements to last.

At this point I am leaning towards aftermarket.

I was going to suggest Webasto - but it looks like they may have exited this segment ? (you can try 'techwebasto' to see what they used to have available). I remember they had a 3-level heater, just like OEM. And I love the heaters in my Envoy - I've said here recently that I think they're the best heated seats I've ever had in a vehicle.

One additional feature that the OEM has - you can select 'back only', as well as both seatback and seat cushion. That would probably be hard to duplicate on an aftermarket basis, unless you rigged up a relay system. I do use this setting myself.

The advantage of going aftermarket - you could keep the cloth seats. With OEM, you'll have to swap leather ones in.

As for the difficulty level - the seats themselves aren't that hard to take out, from what I see others posting here. You'll probably have to get the memory module, as someone else alluded to. And you have the control panels - with the TB, I think the later years put the memory buttons by the door lock, so you might have to get the armrest-based control, plus the door lock panel. And then you have to have them programmed.

Doing it yourself - you'll need at least a pair of hog ring pliers, and I hear that it can be a bit of a pain stretching the upholstery panels to attach to the seats.

But seeing what you've been doing with that engine swap into the Jeep - if you can do that with apparent (?) ease - I'm sure you could get heated seats installed without too much trouble.

 

[l008com]

But seeing what you've been doing with that engine swap into the Jeep...

You DEFINITELY have the wrong guy.

That said, I don't care about the ability to use the back and butt separately. If I got OEM pads, would they hook up to aftermarket switches? Or would I need to splice up custom connectors?

 

[Reprise]

Apologies - I looked up that thread, and it's 'AWD V8' that is doing the engine swap, not you. Maybe you have similar avatars...

I couldn't tell you if the OEM pads would hook up to aftermarket - I don't know enough about how the GM heaters are engineered (or heated seats in general). Connectors would probably be a minor problem compared to resistors, relays, etc., that the seat circuits most likely have.

I'd think if you were going OEM pads, hook them up to OEM components.
If you're doing aftermarket, then same applies for that.

Someone on this board would probably know how to play 'mix & match', and actually rig up something that would work. But you want these working *before* the end of this winter - definitely quicker to go with a fully engineered solution, rather than rigging up one on your own using disparate parts. Safer, too

 

[jsheahawk]

I have a slightly different issue. I grabbed a Rainier power/heated seat from the salvage yard ($25!). The seat has a 9x2 connector, and my '02 LS isn't wired for anything but airbag and seatbelt sensor. I ran a 12V constant wire for the powered seat (both oranges get 12V), and they work great!

Now I want to get the heated seats working. Stock isn't an issue for me; I'll be happy with a couple aftermarket switches mounted on the seat controls. Does anyone know which wires to connect up for this? I've attached a wiring diagram of the plug. Just feeding 12V to the two heated seat supply wires does nothing.

I would have sworn I saw a powered seat conversion thread around here, but I can't find it.

 

[l008com]

Ok I have two new questions, one of which I believe has been answers but I don't know how to read electrical diagrams so I don't know for sure.

First: Do I have an existing 20a heated seat fuse I can tap into? Since my truck has no heated seats but it was an option? If so, what's the best way to tap into it? I know about those add-a-circuit fuse adapters, but is there a wire I could also tap into? A wire that would have been the real power wire for heat?

Second: Where oh where do you guys put the switches, if you do aftermarket seats!?!?
I don't really want them down on the side near the power controls. I'd like them somewhere that's visible. The only place I can think of is placing them top to bottom (instead of next to each other) next to the shifter. But that config is kind of awkward, especially since I haven't seen any switches in generic kits that have 'left' and 'right' arrows on the switches. And the passenger would have to reach around the shifter to turn them on and off. Which isn't terrible but it's also not ideal.

Here's a pic of that space, for people who aren't browsing the forums while IN their trucks

I can't think of a single other place for them, other than that :/ But I'm open to suggestions. Ideally suggestions with pics!

 

[jsheahawk]

I plan to put the switch next to the power seat controls for convenience of install.

I found this wiring diagram online, and I think I'm going to take a stab at it. In low the two pads are connected in series, and switching to high connects them in parallel. I wanted a back only option, but this seems far easier.

 

[l008com]

Another year, another revival of this thread. I keep not getting around to it, but now's a good time to do it. I am single so no gf to complain about having to sit in the back, if I run into trouble and end up driving around with no passenger seat for a while Also at this point my plan is to just go full aftermarket and forget about OEM stuff. I'll literally never use 'back' only anyway.

Above, Reprise said I'd need hog ring pliers (which I also saw in a non-vehicle-specific heated seat install video), but my mechanic says GM uses simple velcro on a lot of newer vehicles. Any chance that's the case here? That will make my life a lot easier.

Also I'm still unsure which kit to buy. There's a million different ones out there, should I just buy one at random, as long as it has buttons I like? Do they come in different sizes? I wouldn't want to end up with cold edges because my pads are too small. As I type this, I'm browsing Amazon and there are plenty on there, but they all seem to be "non brand name" type kits.

Lets talk switches again. It looks like most switches are rocker type that stay down. This is great if you have a remote starter, so you can leave the seats on the night before. But I don't have a remote starter. And I'm planning on putting the switches next to the shifter where you can see them, not on the sides of the seats. I may regret the extra wiring, but I'd much rather have them in a spot where I can see both at a glance, rather than unknowingly driving around for a month with the passenger heater on. I would rather have push-button switches that you can't leave on, like an OEM car. Are different switches from different kits likely to be compatible? If so, I can just search around for switches I like.

BTW how do I remove my center console? I need to do it to install these switches, but I also need to do it before the install, to make sure i *can* install switches there, otherwise I'll have to go with plan B, switches on the sides of each seat.

Last, I've asked further up but I guess I'll ask again because it would be extremely helpful for me. Anyone know of a youtube video or step by step illustrated guide for doing this to a trailblazer? I'm still not entirely sure where i need to stick the wires, how I'm getting from the cab out to the engine (or is the heated seat fuse under the back seat? That would be great!) or how to wired into that box safely.

This time guys, I just might actually do it!!!

 

[jsheahawk]

The TB uses hog rings. I didn't have a set of hog ring pliers, so I just used a couple pairs or needle nose pliers, and I made it work. I reused the hog rings, too.

Consider snagging some seat heaters from the junk yard from a TB/Envoy/Ranier/Saab. It's really easy to see if they're burnt up. I ended up putting the switch for mine on the panel with the seat controls. That eliminated the need to run wires over to the center console, and it let me remove the seats with one plug.

Do it, dude. It's totally worth it!

 

[l008com]

If I get pads from the junk yard, how do I wire it all up? With switches etc? Also are OEM pads that different/better than aftermarket? I'm good at assembly and disassembly (with instructions) but I'm no good at all with splicing/soldering, so I'd like to keep that to a minimum.

 

[jsheahawk]

If I get pads from the junk yard, how do I wire it all up? With switches etc? Also are OEM pads that different/better than aftermarket? I'm good at assembly and disassembly (with instructions) but I'm no good at all with splicing/soldering, so I'd like to keep that to a minimum.

Well, there will be splicing, but I guess you could do it with just crimp connectors. It takes a bit to wrap your head around the wiring diagram, but it're really, really worth it.

Here is my thread on it.

 

[Mooseman]

As far as junker pads, just take the ones from passenger side as driver side is usually broken.

 

[jsheahawk]

As far as junker pads, just take the ones from passenger side as driver side is usually broken.

Yep. And they almost always break on the butt pad right where your thighs rest on the cushion. If you pull one out and there is a black burned spot on the wire...the wire is burnt.

 

[l008com]

I got two sets of dorman pads, installed them tonight. Honestly it was a real pain in the ass. My drivers seat is powered and I could barely lift the thing. Taking the covers off was slow work. 11 hogrings per side. The kit comes with new rings and new pliers, but they're both very shitty, so I just went with zip ties instead. I figure with 11 of them, they should hold good and snug even if one or two break eventually.

The backs were a real pain in the ass. I could not get the covers up very high at all. Getting the pad up underneath without having the adhesive stick where you don't want it to, well that was not fun. But many hours later, I got them both done and back in the truck.

I then went to install the switches, and turns out 25/32nd's is basically 3/4. I never bothered to work that one out in my head, and I do not have a drill bit that large. So I stopped. I drove home tonight with no center console and no shift knob. It's much more awkward doing this than you think it's going to be.

Tomorrow I'll wire them up and if all goes well, I'll be burning my ass from then on!

 

[jsheahawk]

I got two sets of dorman pads, installed them tonight. Honestly it was a real pain in the ass. My drivers seat is powered and I could barely lift the thing. Taking the covers off was slow work. 11 hogrings per side. The kit comes with new rings and new pliers, but they're both very shitty, so I just went with zip ties instead. I figure with 11 of them, they should hold good and snug even if one or two break eventually.

The backs were a real pain in the ass. I could not get the covers up very high at all. Getting the pad up underneath without having the adhesive stick where you don't want it to, well that was not fun. But many hours later, I got them both done and back in the truck.

I then went to install the switches, and turns out 25/32nd's is basically 3/4. I never bothered to work that one out in my head, and I do not have a drill bit that large. So I stopped. I drove home tonight with no center console and no shift knob. It's much more awkward doing this than you think it's going to be.

Tomorrow I'll wire them up and if all goes well, I'll be burning my ass from then on!

It's totally worth it, man.

 

[l008com]

You don't have to tell me. I have very little body fat and I'm always cold unless its 75° or above. I've had heated seats in several past vehicles, I've missed it so much in this truck. But not for long!

 

[l008com]

I got everything together last night. At one point I had both front seats, the center console and one of the rear seats out It's funny how easy it is to get seats out. Running the wires under the rug was a little bit of a pain but not too bad. I had just enough space in my center console to tuck away the two fistfulls of wires. Everything went back together nice, I just need to connect the power and test them out. And I REALLY hope they get toasty warm with no issues.

 

[l008com]

Ok I'm still trying to figure out the wiring.

First off, those three studs sticking up in the fuse box, are those good to ground off to?

Second, one of those fuses is a 20A fuse for the sunroof. That power is on right when I need it. But of I'm potentially pulling 20A of power through whatever wire or feed goes into that fuse holder, is there potential that I'll burn up some internal wiring doing this? If not, I figure I'll just get one of those add-a-fuse things for these smaller style fuse, since the taps included will only work for giant fuses.
The instructions, and most posts on the topic, are very casual about where you connect these seat heater leads. But there's potentially a lot of power being drawn by them.

Also lastly, did you notice how thin the ground is compared to the positive? What's that about? Same amount of electricity comes out as goes in right? Why would the ground be so thin. This isn't like AC where theres a hot and a neutral AND a ground!?

 

[Mooseman]

First off, those three studs sticking up in the fuse box, are those good to ground off to?

I believe so. IFAIK, they are welded to the floor.

Second, one of those fuses is a 20A fuse for the sunroof. That power is on right when I need it. But of I'm potentially pulling 20A of power through whatever wire or feed goes into that fuse holder, is there potential that I'll burn up some internal wiring doing this? If not, I figure I'll just get one of those add-a-fuse things for these smaller style fuse, since the taps included will only work for giant fuses.
The instructions, and most posts on the topic, are very casual about where you connect these seat heater leads. But there's potentially a lot of power being drawn by them.

I'd use the fuse tap. I used one of these for the lighter plug.

Also lastly, did you notice how thin the ground is compared to the positive? What's that about? Same amount of electricity comes out as goes in right? Why would the ground be so thin. This isn't like AC where theres a hot and a neutral AND a ground!?

It could be that the wire that comes with the fuse holder is that size to accommodate 30A. They probably used the proper size wire for the ground.

 

[l008com]

I'm still not connected yet. I can only find 10A fuse taps in stores, I don't want to wait to order one online. Is the way coming out of the tap just a regular connector that I could replace with a thicker wire? Then just pop in a 20A fuse? Still keeping the individual 10A inline fuses.

And the even bigger question, am I going to overload anything or burn anything out by drawing so much extra power out of what was supposed to be a 10amp ignition fuse slot? I have not been able to find any picture of the insides of the fuse boxes, so I don't understand how they work. Do they have one massive 'sheet' of positive rail power, or individual copper wires going to each slot. One of those options will handle a lot more power than the other.

 

[Mooseman]

I don't think you'd burn anything. AFAIK, it's a rail that handles the load of all the fuses on that circuit.

 

[l008com]

I went back to autozone and got the 10amp add-a-fuse, and wired up the drivers side. It's soooooowarm. Also those posts in the middle of the fuse panel are NOT grounded, but there's a ground bolt near by on the base of the box. Just watch out for shorting the battery on the giant positive lead.

So anyway, drivers seat is hooked up and is NICE and warm. I'll order a 20amp online and reconnect them both at a later date. I was betting on the connector wire coming out of the add-a-fuse bracket being a regular connector that I could swap out with a thicker wire, but it wasn't. But now that I have driver's heat, that's enough to hold me over.

I just tapped it off the ignition fuse. I was considering buying the 10a add-a-fuse, and a 30amp relay, and running the seats off the relay, switched by the ignition feed. But meh....