SE Heated Seats In Non-SE Mx-3 + Mod (Pics)

[Nd4SpdSe]

I got a set of heated leather seats from a Canadian '93 GS SE (thanks Havoc!) but oddly enough, the connectors under the center console are not the ones being used on the SE heated seat switches. Fortunately I got a set with both connectors as well as much of the harness as it would let me get to, about 2 inches.

After an attempt on Kp2t's seat transfer, and well as getting a second set of switches at the wreckers, I was able to take the time to take them apart, clean them (something much of been spilt, cause it needed it) and check out how their wired up. Here's the diagram I made up with how I had planned to rewire them to work in my non-SE Mx-3, since i'll have to make my own wiring. As well, the lights in the switches normally are no longer functional, so instead of playing around with and trying to find actual replacement bulbs, i figured might as well put in some LED's, cause LED's are cool, and I want specific colors.



Inside the switch, top (switch) view.


Inside the switch, bottom (wire) view



Mod was much more easy than expected,and cheap too, get the parts from radio shack.
- 2x Blue LED (for the logo) 5v/30mA. PN:276-311
- 2x Red LED (for switch-on) 1.7v/20mA. PN:276-307
- 4x Snap-In LED Holders. PN:276-079 (5 Pack)
- 2x 270-Ohm 1/2w Resistors (For Blue LED on 12v). PN:271-1112 (5 Pack)
- 2x 560-Ohm 1/2w Resistors (For Red LED on 12v). PN:271-1116 (5 Pack)

- 1/4 Inch Drill Bit
- Soldering Iron
- Solder
- Shrink Wrap


First I bored out the old light bulb holes with the 1/4 bit and inserted the LED holder into them (left is with holder, right hole just bored out)



I wired up the Red (switch) LED. Soldering the LED leads directly to the existing soldering points.


And both with the excess leads cut off.


Polarity Markings for the LED's


The resistors for the LED's we're spliced into their respective grounds (in series) for each LED. Had to do it this way since there was no extra room to the resistors inside the switch. The heated seat will be grounded to the chassis, so these resistors will not affect the voltage for the heating pads.



Left was the cover for the bottom cover for the switch. Need to be slightly modified to not hit the connections for the LED.


Just cut away at some of the plastic surrounding the holes for the lights



And the final switch:


Switch all lights off:


Switch blue LED logo on. Will be wired up to turn on with my parking lights.


Switch logo on, as well as the red led that lights up when the switch/heated seats are turned on.

[PATDIESEL]

Nice job, but won't the resistors hold the power flow on the ground for the heat element too, or is there another ground on the heat element for the seat. A tastey bit of injenuity (sp?) in any event.

[Nd4SpdSe]

lol, you got me second guessing on my design, but i just tested with a multi-meter and it does what it does.

Both red and red/black are power and ground for the blue LED, so they don't affect the seat power.

The blue wire is power for the seat as well for the red LED, however, the black ground wire is for the red LED only. It's basically 2 parallel circuits. At this point (the switch portion) in the circuit, 12v volts comes in than splits in two.

1) 12v goes to the LED than before it goes to ground, the inline resistor drops the voltage for the LED, *than* it does to ground through the black wire.
2) 12v comes in through the blue wire as it does for the LED, but it also has an "un-resisted" path out on the green wire. The green wire is 12v hot at this point. From there, it'll go to the seat (or activate a relay, undecided/untested yet), than go to the chassis ground. As long as I ground the seat at any point *after* the resistor (which includes the chassis ground) than it's a 12v circuit.

If I had ran a ground wire back into the switch for some odd reason, and connected it before the resistor (the solering point for the black wire and LED on the switch itself), than yes, it would of been inline with the resistor, and voltage would of been limited.

With this circuit, the switch is 12v hot out on the green wire, which I'm using for OEM heated leather seats, but would easilly be wired to trigger a 12v aftermarket heating pad, or any 12v accessory, heated seat or not, for that matter.

[Nd4SpdSe]

Today I decided to work on the car portion of the mod. I was curious and decided to do some testing of the connectors under the center console. Ironicly, I actually found what I needed from them. My car is a 1992 GS with a manual 5-speed. I can't say or guarantee that they will be the same for all years and models.

On the passenger side connector, there's actually a wire that goes hot when the parking lights are turned on. It's the Red/Black wire. As well, the black wire is just regular ground, which I used as well.


To save space, I cut off the connector entirely and taped/shrink wrapped up the remaining wires. There is a switched 12v source in those wires to it would be a good idea to make sure it's sealed up. I connected the Red wires from the switch to the red/back on my car's harness. And the Red/Black from the switches goes to the black on the car's harness.



This step no longer applies since that line turns off when the brake is pressed
On the drivers side, there's an ignition-on 12v source. The color of that wire is black/yellow. As well on that connectors, there's 2 grounds, the green wire and black wire are both grounds, but I of course only needed one. The rest were taped up.
http://img340.imageshack.us/img340/2395/15xi5.jpg


Switch Wires -> Car Harness
Red -> Red/Black (PS)
Red/Black -> Black (PS)
Blue -> Black/Yellow (DS)
Black -> Black (DS)
Green -> To seat or misc.

Skip this step. The black/yellow wire, although is power source, actually turns off when you press the brake pedal. Ya, not something that's obvious in testing the wires. I thought about splicing from the cigarette lighter but they draw too much where I'll blow the fuse if anything else is plugged in, so you'll have to get/wire up your own ignition switched power source.
The two green wires left will be run to relays. The black/yellow wire isn't thick enough to run one seat, never mind two. I'll get another 12v source for the seat power, which will be triggerd by the relays, which will be triggered through the green wire coming from the swithes


Here's the switches mounted in the car. Although the the switches are installed and functional, with lights and all, the relays and seats aren't hooked up yet, until i get the rest of the necessary equipment (relays, wires and spade connectors) this week.



Switches turned on (which only works when the car's ignition is on)



I waited later in the evening to take some pics. Here's with the logo lights on



Another pic with both logo and switch lights on

[ariesdude]

Nice - I am thinking about getting an universal kit with a massaging unit...

Next project - maybe a heater regulator like this ?
http://cgi.ebay.com/12V-DC-Motor-Speed- ... dZViewItem

[Nd4SpdSe]

Found something interesting, though things went too good...

On the car's wiring side, the ignition wire, is an ignition wire, but actually turns off when you press the brake pedal. Something very unforseen, but what can be used or tapped into is the cigarette lighter, that is an ignition source that's near by, unless you want to run your own, but that is another option.

[MX-3-Tom]

Really nice tutorial!

[Ryan]

Wow! I am DEFINATELY doing this! Most likely with more redneckism! Pick up some old heating pads from a local MCC or thift shop, whatever you want to call it, and rig this up!
Awesome idea, thank you very much It will make the gf VERY happy

[Nd4SpdSe]

Thanks!

Actually, should post an update. This past weekend did a revision on Kp2t's Mx-3.

The boring out the hole for the old light and putting in snap-in LED holders it NOT necessary. LED's actually fit in those holes very snug and nicely. I also found some 12v Red LED's, so there's no need to put an inline resistor on those ones.

Secondly, splicing the heating pads into the cigarette lighter circuit is too much if you have anything else on there (even like a satellite radio receiver), so you'll have to find a constant power source from somewhere else.

[madmdx]

this is very cool !
yes i know this is a bit of an old thread but still interesting. did you find anything other than the 12v to plug it to or no btw?

im just wondering, is it a pain in the a-- to get the dash-part where the heated seats button would be out? (like, as much of a pain in the a-- as getting the front dash off, or less?)

and also, there is a harnesses that comes out from the bottom of my front seats and im curious as to what the hell it is for...

[Nd4SpdSe]

this is very cool !
yes i know this is a bit of an old thread but still interesting. did you find anything other than the 12v to plug it to or no btw?

im just wondering, is it a pain in the a-- to get the dash-part where the heated seats button would be out? (like, as much of a pain in the a-- as getting the front dash off, or less?)

and also, there is a harnesses that comes out from the bottom of my front seats and im curious as to what the hell it is for...

No, I've even tried the cigarette lighter and it would support only the heated seats, so you couldn't actually use the cigarette lighter for anything. It draws more current that I expected, so you're best bet is you run your own 12v source, and have the switches trigger a relay, cause you'll blow the switches circuits.

Lol, taking out the center console section is a breeze...just 4 screws and it slides off.

Hmm, depends, what's connected do your front drivers seat currently is the seat belt sensor, so it knows that your belt is clipped. On the passenger side, if you have anything, it would be a harness for the ABS module.

[madmdx]

lol but i dont have abs (surprisingly, i thought all k8 mx-3's had it)
and umm... im not sure about the seat belt thing. I know my seat belt light turns on for a few seconds when i start the car, but will turn off whether or not i put on my seat belt.

does yours have a harness there as well? i mean its hard to miss... its just there! lol had my mind boggled since day 1

and last time i tried to take off the center dash it took me like an hour and then i just gave up because i wasnt able to... lol maybe i should have looked at a manual

[Ryan]

I don't know how advanced our cars are, but I know lots of models use a small contact type switch in the seat that connects when someone sits on the seat. If it senses someone sitting in that seat, the airbag will go, but if the seat is empty, the airbag does not deploy.

Keeps your sack of potatoes or softening salt safe, too.

Also, of course the seatbelt sensor. Thank goodness our cars don't beep at you...

[stratman1988]

Hey Nd4SpdSe, great HowTo!
I speced out and ordered these components from DigiKey seeing how Radio Shack is long gone.
2X Blue LED
3.5V
DigiKey # 67-1751-ND

2X Red LED
1.7V
Digikey # 67-1648-ND

2X 470 Ohm Resistor for Blue LEDs
Digikey # PPC470BCT-ND

2X 560 Ohm Resistor for the Red LEDs
Digikey # CF12JT560RCT-ND

These parts can be order from http://www.digikey.ca or http://www.digikey.com depending on what side of the border you hail from.

I've just finished restoring the switches in my MX-3 SE updating the lights to LEDs using these components and repairing cracks and broken parts with model airplane glue.

[mitmaks]

nice install