[Ph0zenstone]

they are separate wires, you will need to splice it and add a second connector into the harness

[ins1dez]

But will the electric seats work ? Because i need to move them front and back to install them, otherwise i can't install them.

[JimVR4]

Originally Posted by phozenstone

they are separate wires, you will need to splice it and add a second connector into the harness

I do not think any connectors need to be added into the harness, nor do I think any splices are needed. The existing seat connectors at x275 and x279 will be re-used however wires need to be added into the harness between the seat connectors and the fuse box / junction box.

Ins1dez: The actual wiring hookups that you need depend on the model year of your car. The fuse box / junction box has different fuse numbers and pinouts for different years. You will have to consult WDS (Wiring Diagram System) and download the fuse box diagram and compare it to the white sheet in your glove box rear panel.

Once you have identified the correct fuses, you will need to connect heavy guage (probably 12 guage) wiring from the fuse box to the X275 and X279 connectors. Each seat connector will need two wires, one for +12V and one for ground.

Then you need to make sure the CAN bus wiring is present at the seat connectors. You may have to add wiring between the junction box and the seat connectors for this.

Finally you have to code the car for electric seats with memory. I'm not sure the seats will operate at all unless the coding is performed first. Read the thread from post #1 and good luck.

[ins1dez]

I think you don't understand my question. Right now i have manual seats heated, that means i already have a + , and electricity on the seats. I know that for memory seats i need another + and i need to code them, but my problem right now is if i put the seats on the car, will they work front and back ?

I need to know this because i need to move them front and back so i can put the screws back together. If i can't move them i can't install them.

So just for moving front and back, do i need any other wires, or the connector from the heated seats will provide electricity for moving the seats ?

[JimVR4]

I understood your question. The motors and seat heating use different wires for powering so i doubt the electric seats will receive power if you do not do the wiring first.

You can easily check by unscrewing your seats, unplugging the seat connector and examining the harness to the seat connector to see if the power wires are present. If memory serves they are pins 4,8,9, and 13. All should be present for both electric and seat heating.

[ins1dez]

You need to open the yellow connector otherwise you won't see nothing. The wires which come into the connector are wrapped with a foil or something

[JimVR4]

Originally Posted by ins1dez

You need to open the yellow connector otherwise you won't see nothing. The wires which come into the connector are wrapped with a foil or something

Are you answering your own question lol? Yes you have to take apart the yellow connectors (x275 and x279) to see what wires are present.

[ins1dez]

How do you take them off ?

[JimVR4]

Originally Posted by ins1dez

How do you take them off ?

Start by opening or cutting the zip tie. The yellow housing slides off after you release the tiny clips. I believe there is also a black or grey part that comes off as well.

[bolind]

If one is a lazy bastard and just wishes to buy the factory BMW harnesses, what are the part numbers, and how is it done?

I currently have unheated, manual seats, and a very meager harness. I'm switching in leather power sports seats with heat and adjustable lumbar support.

[JimVR4]

Originally Posted by bolind

If one is a lazy bastard and just wishes to buy the factory BMW harnesses, what are the part numbers, and how is it done?

I currently have unheated, manual seats, and a very meager harness. I'm switching in leather power sports seats with heat and adjustable lumbar support.

It will be a TON more work and cost to install complete factory harnesses. If you want to be lazy go and find a dealer that will work with you to install and code the upgrade.

If you want to keep the costs to a reasonable level be prepared to DIY and

[Ph0zenstone]

retrofitting the harness wasn't that hard at all as long as you have the correct pin connectors. What i did was route one power and one ground into each of the harnesses; split each wire into two so that you have a total of 2 power and 2 ground going into each of the driver and passenger harness. I had 2 power and 2 ground as the motors for front/rear and motors for the lumbar/bolsters were powered by 2 separate pins. Essentially i did not have to mess with the seat itself, i just retrofitted power wires into my existing wiring inside the car. By doing it this way, i am able to swap other power seats into my car in the future without having to redo the wiring.


Here are some updated pics:

[eml58]

I am replacing my 2007 3028xi manual heated seats with power / heated seats and want to bench test the mechanical operation not heat of them, I tried to hook up an old battery to the power spades but couldn't get them to operate any suggestions???? Thanks

[Ph0zenstone]

Originally Posted by eml58

I am replacing my 2007 3028xi manual heated seats with power / heated seats and want to bench test the mechanical operation not heat of them, I tried to hook up an old battery to the power spades but couldn't get them to operate any suggestions???? Thanks

They Have to be connected to the canbus wiring and not only the battery

[bolind]

First of all, MAN those M3 seats look rad!

Second eml58, some people report success by bench testing their seats with a dumb power supply, others seem to require a CAN signal to make them work...

Originally Posted by bolind

If one is a lazy bastard and just wishes to buy the factory BMW harnesses, what are the part numbers, and how is it done?

I currently have unheated, manual seats, and a very meager harness. I'm switching in leather power sports seats with heat and adjustable lumbar support.

So I've investigated further, and the harnesses I found on bmwfans.org turned out to be the actual harness in the seat itself, which I, obviously, have. The car's harness can't just be purchased, as it's pretty integral to the car.

So I'm trying to put together a list of what one would need to expand the existing harness. Keep in mind my car currently have next to nothing. I've checked, and all that runs to the seats are airbag, seat belt tensioner and, for the passenger side, occupancy sensor.

Wiring will be sponsored by my workplace, so no need to worry about that. It's just stranded wire in the right thickness.

The connector housing(s) on the car harness side are the same, just not populated, so first we need some extra female connectors, numbers: 61131383776 and 61138364844.

Then we need something at the other end? The CAN connectors; they're just the small ones too? How about the PWM signal from the junction box? Do I need a socket housing?

How about the fuse panel? Do we tap into an existing 30A fuse, or what will be needed to establish an additional fuse?

[Ph0zenstone]

To answer some of your questions;

The female connectors - make sure you buy 2-3 extra of each one because they are so small and delicate that i broke a few in the process. BMW also doesn't stock them so it was a pain to have to wait for them to come in (usually 2-3 days).

For EACH seat harness (your car's harness, not the seat) you will need to do the following:
1) Add a power wire by connecting one end to the female connector that goes into the harness and the other end should be tapped into the fuse box behind the glove compartment (30A fuse).
2) Add a ground wire by connecting one end to a female connector that goes into the harness and add a ring terminal to the other end which will be used to mount into the same hole as the seat.
3) If you have power bolsters like mine, you will need to add a splitter into each of the above wires and also route them into the car's harness (e.g. you will have 2 power female connectors and 2 ground female connectors now in your harness instead of just one of each)
4) Now you need to add kcanbus wiring to your car's harness. I found that the easiest way to do this was using 14 guage speaker wire as it already has positive/negative on it. Follow the wiring diagram and wire one wire into each terminal using the BMW female connectors; the other end will have to connect to anywhere that you can easily locate with kcan wiring (i believe it was green and green/orange). I found it right near the same fuse box i used for the power wire. Simply tap into that wiring and you're good to go!
5) Have a beer and celebrate cuz you now have powered seats! You'll also realize how happy you are with using oem bmw harnesses instead of some other members who hardwired it because now you can swap other seats if you get bored with the existing seats and you don't have to redo all the wiring.

[bolind]

Originally Posted by phozenstone

The female connectors - make sure you buy 2-3 extra of each one because they are so small and delicate that i broke a few in the process. BMW also doesn't stock them so it was a pain to have to wait for them to come in (usually 2-3 days).

Gotcha. I might as well order them online then. They cost peanuts, so I'll just grab a handful.

Originally Posted by phozenstone

1) Add a power wire by connecting one end to the female connector that goes into the harness and the other end should be tapped into the fuse box behind the glove compartment (30A fuse).

OK, do I need to establish a new seperate fuse? Bear in mind, I don't have heated seats or anything right now. Or do I just grab whatever 30A fuse there is?

Originally Posted by phozenstone

2) Add a ground wire by connecting one end to a female connector that goes into the harness and add a ring terminal to the other end which will be used to mount into the same hole as the seat.

Is this the official way for the ground? Wouldn't it be more proper to route it back to the fusebox as well?

Originally Posted by phozenstone

3) If you have power bolsters like mine, you will need to add a splitter into each of the above wires and also route them into the car's harness (e.g. you will have 2 power female connectors and 2 ground female connectors now in your harness instead of just one of each)

I have power bolsters. So it's cool to run bolsters and servos off the same 30A fuse/power cable?

Originally Posted by phozenstone

4) Now you need to add kcanbus wiring to your car's harness. I found that the easiest way to do this was using 14 guage speaker wire as it already has positive/negative on it. Follow the wiring diagram and wire one wire into each terminal using the BMW female connectors; the other end will have to connect to anywhere that you can easily locate with kcan wiring (i believe it was green and green/orange). I found it right near the same fuse box i used for the power wire. Simply tap into that wiring and you're good to go!

I'm with you on the CAN wiring, but my passenger seat needs a PWM'ed power feed for the heat. How does this connect at the other end (some junction box?)

Originally Posted by phozenstone

5) Have a beer and celebrate cuz you now have powered seats! You'll also realize how happy you are with using oem bmw harnesses instead of some other members who hardwired it because now you can swap other seats if you get bored with the existing seats and you don't have to redo all the wiring.

Agreed, although these seats are probably going to stay in this car, I want to do this right the first time around.

Thanks for your answers! I would really like to tear into this as prepared as possible, as the car can't be off the road for too many days in a row.

[woodpecka]

Guy, there are a few hints:

You need to add the kcan on the driver seat only. The passenger doesn't has memory.
During my research, I did found that it's recommended to use a twisted double cable to avoid issue on the kcan interference.

If you have already some power for the heating or side or lumbar, you can reuse these cable for the other functions. You just have to jump the positive and negative at the connector level.

Cheers

[glennwa]

(sorry about the double post, the other thread looks sort of.... dead)

Hi folks. I am moving from manual HEATED non-sport seats, to sport, heated, power/memory seats. I tried swapping and just plugging in connectors as is... and got nothing working. I thought I'd at least be able to get forward/backward/tilt/recline functionality.... but it didn't work.

If I'm not concerned about the memory function working (would be nice but not that big a deal) how might I wire this to get it working?

Thanks
-Glenn

[glennwa]

Folks - looks like this thread is dead. Unfortunately I'm stuck!

I have both seats working for directional adjustment. What doesn't work on either seat are the adjustable bolsters and the lumbar support.

I noticed my old seat has a blue lead going to pin 1. Anyone know what this is, and should I worry that the new seat doesn't have a female pin for it?

It also looks like the NEW seat is expecting a wire on pin 7, which looks like red and black? I didn't run a wire to this lead, which may be my problem. Anyone know what this lead is for?

Thanks
-Glenn

[andy_06xi]

When I swapped my seats -- the lumbar and bolsters didn't work -- but everything else did. I found the ground for these functions (on the seat side) was different than the rest of the seat. My seat side connector had 2 brown ground wires going to the connector -- but the car side connector had on one brown ground wire coming in. I shorted the two brown wires on the seat side and this got everything working.

[glennwa]

Thanks, Andy_06xi. I actually caught that and shorted them as well.

I think there is another wire though I need to run. I guess I will just take a chance and try to match up the colors...

Thanks
-Glenn