Heated seats/Trac Cotrol?
12-09-02, 12:54 PM
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Heated seats/Trac Cotrol?
I have a93 SC400 originaly bought in the South East it does not have the heated seats or trac control options I'm a soldier Stationed in Northern New York And it's cold as Hell up here. So has anyone converted or added these options to their car before?
Last edited by LEXBOGGY; 12-09-02 at 12:55 PM.
12-09-02, 06:14 PM
#3
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Here's the deal on what myself and some others have noticed about non-factory heated seats.
A car with no heated seats is *somewhat* wired already from the factory for the option. Cars with heated seats have a different set of seats and the wires ran under the carpet are a different also. It would be *theoretically* possible to swap the seats, change the wires, and the fuse and switches then have factory style heated seats.
This route is much more complicated than just buying aftermarket seat heaters and having a upholstery shop install them. You could do this yourself, as I know one member with an SC bought a new leather kit, heated seats and the massage system and installed it himself. They heat up faster and would be new.
I'm can't remember the the pricing, nor the brand of the aftermarket seat heaters, but I'm sure someone here knows. \
Traction control? Adding this? Wheew... I dunno about that one. Maybe the SC dash and system is different, but I know on my LS the dash (speedo/tach) screen is different for a car with the traction control system. *I think*...
A car with no heated seats is *somewhat* wired already from the factory for the option. Cars with heated seats have a different set of seats and the wires ran under the carpet are a different also. It would be *theoretically* possible to swap the seats, change the wires, and the fuse and switches then have factory style heated seats.
This route is much more complicated than just buying aftermarket seat heaters and having a upholstery shop install them. You could do this yourself, as I know one member with an SC bought a new leather kit, heated seats and the massage system and installed it himself. They heat up faster and would be new.
I'm can't remember the the pricing, nor the brand of the aftermarket seat heaters, but I'm sure someone here knows. \
Traction control? Adding this? Wheew... I dunno about that one. Maybe the SC dash and system is different, but I know on my LS the dash (speedo/tach) screen is different for a car with the traction control system. *I think*...
Last edited by Lvangundy; 12-09-02 at 06:14 PM.
12-09-02, 07:23 PM
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Heh....traction control. Kiss that one goodbye unless you plan on spending waaaay more than the car is worth in parts and labor....there are a gazillion different parts you'd have to swap....some of the more expensive items being the ABS actuator, and the ABS/TRAC computer, you might need a new engine ECU as well, since that interfaces with the TRAC computer.
Heated seats.....the factory seat heaters are pretty lame....you might as well go aftermarket, and find a set of stock switches.
Heated seats.....the factory seat heaters are pretty lame....you might as well go aftermarket, and find a set of stock switches.
12-10-02, 02:07 AM
#5
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The aftermarket traction control systems (like the Race Logic, etc.) are actually superior as far as getting optimal acceleration with minimal wheelspin, don't know if you were just thinking snow traction, but these things are pretty worthless in the snow anyways. The aftermarket seat heating systems are superior as well, the SC heaters are pretty crappy, never get really hot enough to toast my package 
.....
- LL
.....- LL
06-02-14, 10:48 PM
#7
Yeah yeah, I know, 12 year old thread bump... 
I have non-heated seats but am in need of reupholstering the driver's seat, so I picked up an OEM seat heater and shift bezel with the heater controls in hopes of tying that in at the same time. This post makes me think the wiring will be tougher than envisioned, though.
Why would the wiring under the carpet be different if the non-heated setup has the heater/traction 11-pin harness (that matches the heater controls) under the console? I haven't traced where that goes, but I assumed it runs under the carpet and splits off to the seats where it simply doesn't connect to anything. My hope was that the seat has the heater inputs and nothing connected to the 3-pin connector (see below) for the heater itself, but that might have been wishful thinking.
Any idea what the fuse requirements are for seat heaters? Is it shared with something else or have its own fuse that's probably empty in my setup?
I'll also need to figure out a way to test if my seat heater even works, being basically an untested throw-in with other stuff I was ordering, to have the OEM plug for potentially splicing onto an aftermarket heater to tie into what I figure/figured is the OEM wiring in the seat. It's a 3-pin orange connector with red, white, and green wires. That sounds like typical hot/neutral/ground wiring, so maybe I can hook it up to a battery to test.
A car with no heated seats is *somewhat* wired already from the factory for the option. Cars with heated seats have a different set of seats and the wires ran under the carpet are a different also. It would be *theoretically* possible to swap the seats, change the wires, and the fuse and switches then have factory style heated seats.
Why would the wiring under the carpet be different if the non-heated setup has the heater/traction 11-pin harness (that matches the heater controls) under the console? I haven't traced where that goes, but I assumed it runs under the carpet and splits off to the seats where it simply doesn't connect to anything. My hope was that the seat has the heater inputs and nothing connected to the 3-pin connector (see below) for the heater itself, but that might have been wishful thinking.
Any idea what the fuse requirements are for seat heaters? Is it shared with something else or have its own fuse that's probably empty in my setup?
I'll also need to figure out a way to test if my seat heater even works, being basically an untested throw-in with other stuff I was ordering, to have the OEM plug for potentially splicing onto an aftermarket heater to tie into what I figure/figured is the OEM wiring in the seat. It's a 3-pin orange connector with red, white, and green wires. That sounds like typical hot/neutral/ground wiring, so maybe I can hook it up to a battery to test.
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06-03-14, 05:33 PM
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I wouldn't worry about the traction control or heated seats. I'm deleting all the unnecessary stuff on my car, abs, heated seats, I might even convert to manual windows
I just like things simple, and I've never seen an sc or soarer converted to manual windows. I've searched everywhere.
I just like things simple, and I've never seen an sc or soarer converted to manual windows. I've searched everywhere.
06-03-14, 05:54 PM
#9
I wouldn't worry about the traction control or heated seats. I'm deleting all the unnecessary stuff on my car, abs, heated seats, I might even convert to manual windows
I just like things simple, and I've never seen an sc or soarer converted to manual windows. I've searched everywhere.
I just like things simple, and I've never seen an sc or soarer converted to manual windows. I've searched everywhere.
06-03-14, 06:01 PM
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I had a corolla, loaded with every option lol.
I just want it to be different, and to **** guys off who think that an sc300 is a untouchable luxury car. Lol
Which they were 20 years ago, But these cars are cheap and a great platform to build on. They just need to be a few pounds lighter. Which is the main reason I'm getting rid of all the extra stuff like the abs, factory seats and so on.
I'm not gutting the car, just shaving weight I can and cleaning up the engine bay in the process.
So if anyone needs an ABS module, I have 2 of them.
I just want it to be different, and to **** guys off who think that an sc300 is a untouchable luxury car. Lol
Which they were 20 years ago, But these cars are cheap and a great platform to build on. They just need to be a few pounds lighter. Which is the main reason I'm getting rid of all the extra stuff like the abs, factory seats and so on.
I'm not gutting the car, just shaving weight I can and cleaning up the engine bay in the process.
So if anyone needs an ABS module, I have 2 of them.
06-04-14, 10:36 AM
#11
I think the direction of the thread is to add stuff, not remove it but thatnks for the insight Jimbow.
I wouldn't doubt that the connectors are the same, but maybe the wire or 2 is missing from it, or maybe its there and the same. I think that is what they meant by different is the wires being there or not already, not that the connectors are different. alot of times on the higher end cars like ours the wires will be there actually, so its worth a look, but I am positive you can get them to work with a switch. the heater circuit probably just needs a fused power source and a ground with a switch, doesn't matter if its wired OEM or not, you can even make your own relay and whatnot and use the OEM switch to keep it OEM looking.
If the wires are there they just save you from installing a fused relay int he engine bay and running wires, switch is just a switch and the heaters are not complicated just an on off. now on other lexus models there is a high and low setting, and well then you would have to build a more complicated setup to retain the 2 settings. likely one is getting normal power like the 1 setting above, and for the lower setting there is likely some heatsink resistor inline somewhere or a circtuit that drops the current/voltage to it. kind of like for 2 speed fuel pumps.
Trac control is never worth installing on a toyota without it, you are changing so many things including the way the brake system works and extra computers and body wiring is different, its 100% all of time a much better idea to sell your SC and buy a model that came with the heated seats/trac control, aka the winter package.
I like the heated seats so much in the winter I don't even want a car without them anymore. My car is a 5 spd so no trac control, but I used to have an auto that had it and it was a nightmare if you do loose control is cuts off the power so you end up just sliding whatever direction you were last going, you cannot power out of it and correct.
100% of the time just taking your foot off the pedal when you start to slip is exactly what the trac control does anyways... so just take your foot off the gas and you should be fine. trac control is only marginally helpfull Its really the most annoying option in the world IMO on these older cars they just snap the throttle body shut, so just take your foot off the gas and call it trac control.
I wouldn't doubt that the connectors are the same, but maybe the wire or 2 is missing from it, or maybe its there and the same. I think that is what they meant by different is the wires being there or not already, not that the connectors are different. alot of times on the higher end cars like ours the wires will be there actually, so its worth a look, but I am positive you can get them to work with a switch. the heater circuit probably just needs a fused power source and a ground with a switch, doesn't matter if its wired OEM or not, you can even make your own relay and whatnot and use the OEM switch to keep it OEM looking.
If the wires are there they just save you from installing a fused relay int he engine bay and running wires, switch is just a switch and the heaters are not complicated just an on off. now on other lexus models there is a high and low setting, and well then you would have to build a more complicated setup to retain the 2 settings. likely one is getting normal power like the 1 setting above, and for the lower setting there is likely some heatsink resistor inline somewhere or a circtuit that drops the current/voltage to it. kind of like for 2 speed fuel pumps.
Trac control is never worth installing on a toyota without it, you are changing so many things including the way the brake system works and extra computers and body wiring is different, its 100% all of time a much better idea to sell your SC and buy a model that came with the heated seats/trac control, aka the winter package.
I like the heated seats so much in the winter I don't even want a car without them anymore. My car is a 5 spd so no trac control, but I used to have an auto that had it and it was a nightmare if you do loose control is cuts off the power so you end up just sliding whatever direction you were last going, you cannot power out of it and correct.
100% of the time just taking your foot off the pedal when you start to slip is exactly what the trac control does anyways... so just take your foot off the gas and you should be fine. trac control is only marginally helpfull Its really the most annoying option in the world IMO on these older cars they just snap the throttle body shut, so just take your foot off the gas and call it trac control.
Last edited by Ali SC3; 06-04-14 at 10:41 AM.
06-04-14, 11:03 AM
#12
Thanks, Ali. You got the gist of where I'm going with this.
The plug on the shift bezel w/ heat/trac matches the empty plug under the shifter on my car without seat heaters. Both are the same 11-pin configuration with the same 3 pins blank. The only difference is, the wires are somewhat different colors. (Now that I'm cross checking them, it's mostly the traction control colors that differ.) Not sure why that would be, but maybe it's a difference by year.
It doesn't make sense that Lexus would put that empty plug there and not have it connect up to something, be it a power source and/or the wiring bundle under the carpet to the seats.
4 of the 8 wires are for the traction switch, which I'm not concerned with. The heater controls have 2 wires per seat, and I'm only trying to get the driver's seat working for now, so I just need to look for those two under the seat... They're white w/ black stripe, and blue w/ red marks (Star Trek looking wedges, not the usual dots) on my replacement bezel. On my empty plug under the shifter, that corresponds to white w/ black stripe and silver dots, and blue w/ silver dots. That's good, they're basically the same!
Next up will be seeing what's under the seat... I see one of two options (most likely scenarios) at that point:
1) The two wires dead end at the main plug below the seat. This is more likely than I was originally thinking, as the entire seat is different for with/without heaters, so it wouldn't really save Lexus any manufacturing trouble by running the heater wiring through the seat for setups that don't utilize it, unlike the wiring under the carpet that needs to be laid down for everything. If this is the case, I would need to tap into them prior to the main plug and run that signal directly to a heater.
2) They connect to the seat's main plug and dead end where the orange 3-pin connector on the seat heater lines up. If so, there would be an empty plug there, like there is currently below the shifter. This is the best case scenario, as I can hook my OEM heater in directly (I tested it yesterday with a 9V battery and got nothing, but I was guessing at ground and may not have been supplying enough juice) or cut off its connector and splice it to an aftermarket one.
If anyone has any guesses about the fusing, that would be hugely helpful. Like you said, the switch is a simple thing. It just needs to be connected to power. And my hunch is, the 11-pin connector has power, just no fuse. (Unless it's shared with something else.)
Edit: I'm guessing one of the wires is power to the switch and the other is an on/off signal to the seat heater? If so, I only have one wire to look for under the seat.
The plug on the shift bezel w/ heat/trac matches the empty plug under the shifter on my car without seat heaters. Both are the same 11-pin configuration with the same 3 pins blank. The only difference is, the wires are somewhat different colors. (Now that I'm cross checking them, it's mostly the traction control colors that differ.) Not sure why that would be, but maybe it's a difference by year.
It doesn't make sense that Lexus would put that empty plug there and not have it connect up to something, be it a power source and/or the wiring bundle under the carpet to the seats.
4 of the 8 wires are for the traction switch, which I'm not concerned with. The heater controls have 2 wires per seat, and I'm only trying to get the driver's seat working for now, so I just need to look for those two under the seat... They're white w/ black stripe, and blue w/ red marks (Star Trek looking wedges, not the usual dots) on my replacement bezel. On my empty plug under the shifter, that corresponds to white w/ black stripe and silver dots, and blue w/ silver dots. That's good, they're basically the same!
Next up will be seeing what's under the seat... I see one of two options (most likely scenarios) at that point:
1) The two wires dead end at the main plug below the seat. This is more likely than I was originally thinking, as the entire seat is different for with/without heaters, so it wouldn't really save Lexus any manufacturing trouble by running the heater wiring through the seat for setups that don't utilize it, unlike the wiring under the carpet that needs to be laid down for everything. If this is the case, I would need to tap into them prior to the main plug and run that signal directly to a heater.
2) They connect to the seat's main plug and dead end where the orange 3-pin connector on the seat heater lines up. If so, there would be an empty plug there, like there is currently below the shifter. This is the best case scenario, as I can hook my OEM heater in directly (I tested it yesterday with a 9V battery and got nothing, but I was guessing at ground and may not have been supplying enough juice) or cut off its connector and splice it to an aftermarket one.
If anyone has any guesses about the fusing, that would be hugely helpful. Like you said, the switch is a simple thing. It just needs to be connected to power. And my hunch is, the 11-pin connector has power, just no fuse. (Unless it's shared with something else.)
Edit: I'm guessing one of the wires is power to the switch and the other is an on/off signal to the seat heater? If so, I only have one wire to look for under the seat.
Last edited by t2d2; 06-04-14 at 11:09 AM.
06-04-14, 11:55 AM
#13
I found a few useful things. Single fuse for both seat heaters. Wiring to the seats is part of the same power controls harness, as I figured.
https://www.clublexus.com/forums/sc-...seat-fuse.html
Off to see if I can find that labeled in the kick panel fuse box...
https://www.clublexus.com/forums/sc-...ted-seats.html
So simple! Plop a fuse in and connect up the replacement bezel, and even if it's not connected to a seat heater, I should know instantly by the indicator lights on the switches if that aspect is working. From most accounts, the OEM heaters are really weak. So, if I can get power to the switches, it might be best to abandon trying to tie in the OEM heater and just wire in an aftermarket one at that point, keeping the OEM look with the switches.
https://www.clublexus.com/forums/sc-...seat-fuse.html
I'm trying to find the fuse to the driver seat. I looked on the driver side kick panel the only fuse there is seat heater...
https://www.clublexus.com/forums/sc-...ted-seats.html
when I flip the switches for them, the light indicating they're on does come on.
06-04-14, 01:54 PM
#14
Pgs 190-191 of the factory service manual (pg 4049-4050 of the PDF) cover the seat heater wiring. I can make sense of some of the schematics, but it's not a strong point for me...
Should the kick panel fuses have a cover with their labeled positions? I'm guessing I'm missing that.
T12 (A) is the 11-pin connector I mentioned above. I'm not sure what S24 (B) refers to. It's a 6-pin connector, according to the end of pg 191.
I don't quite understand what this means:
T12 SEAT HEATER SW
7–GROUND : APPROX. 12 VOLTS WITH SW AT ON POSITION
8–GROUND : ALWAYS CONTINUITY
Is that saying the #7/8 pins are ground or power?? #8 is the white w/ black stripe for the driver's seat, while #7 is the corresponding one for the passenger seat.
I have the S16 orange harness/heater for the cushion but didn't receive the S15 seat back one. So, an aftermarket set might do me better, anyway.
It took me a bit to find the right page numbers in the FSM PDF, with everything being in some bizarre alphabetical order, rather than page order, but pg 20 (pg 4034 in the PDF) covers the kick panel relay blocks.
Pg 23 (4037) shows the seat heater fuse and relay being on R/B No. 4, which is on the front side of J/B No. 1 ... unfortunately, "front side" means the side up against the fender. Good golly is that ever difficult to get to! The 15A fuse holder and relay (I sure hope I have that in place, otherwise I'll have to go through this a few times) should be back there somewhere, but I havne't managed to get to them yet. There are two bolts holding the bottom of the main J/B N. 1 fuse panel in place, and one up top according to the illustration. I had to loosen that top one by hand, being pretty much impossible to get a tool on. Did they think no one would ever need to replace one of the backside fuses?
I still can't seem to get the J/B No. 1 panel free, though. Do I need to disconnect all its plugs to remove tension?
Should the kick panel fuses have a cover with their labeled positions? I'm guessing I'm missing that.
T12 (A) is the 11-pin connector I mentioned above. I'm not sure what S24 (B) refers to. It's a 6-pin connector, according to the end of pg 191.
I don't quite understand what this means:
T12 SEAT HEATER SW
7–GROUND : APPROX. 12 VOLTS WITH SW AT ON POSITION
8–GROUND : ALWAYS CONTINUITY
Is that saying the #7/8 pins are ground or power?? #8 is the white w/ black stripe for the driver's seat, while #7 is the corresponding one for the passenger seat.
I have the S16 orange harness/heater for the cushion but didn't receive the S15 seat back one. So, an aftermarket set might do me better, anyway.
It took me a bit to find the right page numbers in the FSM PDF, with everything being in some bizarre alphabetical order, rather than page order, but pg 20 (pg 4034 in the PDF) covers the kick panel relay blocks.
Pg 23 (4037) shows the seat heater fuse and relay being on R/B No. 4, which is on the front side of J/B No. 1 ... unfortunately, "front side" means the side up against the fender. Good golly is that ever difficult to get to! The 15A fuse holder and relay (I sure hope I have that in place, otherwise I'll have to go through this a few times) should be back there somewhere, but I havne't managed to get to them yet. There are two bolts holding the bottom of the main J/B N. 1 fuse panel in place, and one up top according to the illustration. I had to loosen that top one by hand, being pretty much impossible to get a tool on. Did they think no one would ever need to replace one of the backside fuses?
I still can't seem to get the J/B No. 1 panel free, though. Do I need to disconnect all its plugs to remove tension?
06-04-14, 02:26 PM
#15
I think its saying 7 is a 12V wire, and 8 is the ground since its always continuous with ground.
Its really hard to say which way its wired I haven't looked at the schematic at all.
there could be a relay stock, or it could be a more simple connection.
since the switch can come on without the heater working according to that thread I would lean towards relay, as if it was power straight to the seat and then the switch on the ground side, it wouldn't light up without the seat having current going through it. on the other hand it could be the switch is the relay itself, I haven't looked at one closely to see how many wires are coming out of it, if just 2 then a plain switch, if more then likely a relay.
I was wondering if it was 12v heater so you answered that pretty much.
all 12V wires in the car that already have power are fused, question is how much and can it handle the additional amps even if you tapped into an existing circuit.
If the fuse is not there already I would guess alot of the other stuff is missing, I would just install it externally like an aftermarket one. I can remove my bezel and take a picture of the wires going into the heater buttons if that helps any.
what I would do is get a 30 amp or so relay, wire up the power and ground to the seat, and then wire up the relay to come on when the switch is turned on by connecting one side of the relay to battery power and the other side to the switch, and then the other terminal on the switch to ground. then the switch turns on the relay and that turns on the heaters, and since its connected to the battery you should have good heating and no problems with drawing too much current.
thats just general relay wiring though off the top of my head, maybe check aftermarket heater wiring diagrams maybe there is a better way.
Its really hard to say which way its wired I haven't looked at the schematic at all.
there could be a relay stock, or it could be a more simple connection.
since the switch can come on without the heater working according to that thread I would lean towards relay, as if it was power straight to the seat and then the switch on the ground side, it wouldn't light up without the seat having current going through it. on the other hand it could be the switch is the relay itself, I haven't looked at one closely to see how many wires are coming out of it, if just 2 then a plain switch, if more then likely a relay.
I was wondering if it was 12v heater so you answered that pretty much.
all 12V wires in the car that already have power are fused, question is how much and can it handle the additional amps even if you tapped into an existing circuit.
If the fuse is not there already I would guess alot of the other stuff is missing, I would just install it externally like an aftermarket one. I can remove my bezel and take a picture of the wires going into the heater buttons if that helps any.
what I would do is get a 30 amp or so relay, wire up the power and ground to the seat, and then wire up the relay to come on when the switch is turned on by connecting one side of the relay to battery power and the other side to the switch, and then the other terminal on the switch to ground. then the switch turns on the relay and that turns on the heaters, and since its connected to the battery you should have good heating and no problems with drawing too much current.
thats just general relay wiring though off the top of my head, maybe check aftermarket heater wiring diagrams maybe there is a better way.