Lettut

Hi folks



Maybe someone on the forum with electrical skills can help me out with this (stupid and boring) wiring question?

I´d like to install a pair of -92 sc300 seats into a -95 jdm supra that I´m lhd-converting. lhd supra seats are hard to find, so I´d like to use the sc300 seats that I have instead
I can´t figure out how to get the power seat function to work safely. I´m afraid that I´ll toast the seat ecu if I connect it the wrong way







Here´s the sc -92 wiring diagram








A) The seat plug on the supra body harness has only two wires, 12V and ground

B) the 14pin seat plug on the sc300 drivers seat (Ba1) has 10 wires that connects to the seat ecu.
1 Empty
2 B-R from battery via (40AIGSW) and via ignition switch
3 R from battery via (10A dome)
4 W connects with seat position memory via the tilt/telescope ecu
5 Empty
6 GR from battery via (10A gauge) and parking position sensor
7 L-W (thick wire) from battery via (30A door)
8 G-W from battery via (15A stop) and stop light switch
9 B connects with seat position memory via the tilt/telescope ecu
10 Empty
11 L-B ?
12 W-B (tick wire) ground
13 BR-B ground
14 Empty (seat heater)

I´ve tried to connect nr7(L-W) (thick wire) and nr 12(w_B)(thick ground) to a battery, but everything was dead (never tried with nr13 ground)

I presume that nr 2 (ignition), nr 6 (parking position) and nr 8 (stop light switch) needs to be powered to make the ecu work?
Will it be safe to hook them up together with nr 7(L-W) (the thick wire)?


Do you think it will be possible to make this work with the single 12V wire that´s on the supra seat plug?

Should I look for some supra seats instead?



Any help/advice would be very appreciated!

gerrb

iTrader: (34)

what's up buddy .. how are your MKIV and SC projects going on ?

You would need more than the + and - voltage supply to get the seats working.

If you observe the diagrams , there are other ground points that is the reason there would be no movements if you have the main power supply connected powering the seat ECUs.

Lettut

Hi Gerry


You were right of course . It worked when I connected all the ground wires.
Thank you!

The LHD-conversion of the black Supra is 90% finished. The wiring has been the most time consuming part. I´ve converted the rhd body harness into lhd. A lot of soldering and heat shrinking.
Looking forward to start an SC-project with your parts after this .

gerrb

iTrader: (34)

Anders - glad things work out !

Mehtab

Hi Lettut,

I know this post is more than 4 years old, but I would like your help

Which wires did you connect Ground and Positive respectively to run the Seat controls

Best Regards

Lettut

Hi Mehtab
Sorry for a late reply!
Here´s the seat wiring on a -95 Supra (jdm and usdm are the same)
Bq1 -1 (blue/white is 12v
Bq1-2 (white/black) is ground


I´ve tried to find some pictures of how I connected the seats, but I´m afraid I can´t find any. I used some spare conncetors that replaced the supra-connector (Bq1) on the floor and the sc-connector on the seat.
It was four years ago , so I can´t guarantee anything, but according to the diagram it should be:
Ba1-6 Gray to 12v

Ba1-12 White/black to ground
Ba1(2?)-13 Brown/black to ground

Please correct me if I´m wrong, but I think that the 3 wires above is enough to make it work. I think that the other wires(below) is for belt tensioner,seat memory etc,. Not needed for the basic functions.
Ba1-2 Brown/red
Ba1-7 Blue/white
Ba1-3 red
Ba1-8 Green white
Good luck!

Mehtab

Dear Lettut,

Thank you very much, I really appreciate your reply.

It worked
Ba1 -6 Gray is 12+
Ba1 -7 Blue White is 12+

Ba1 -12 White-Black is 12-
Ba1- 13 Brown-Black is 12-

emoylv

Hello. What year are your seats? I have 2006 SC430 seats and can get everything to work except the front and rear elevator motors. I attached Blue/white to power and both White/black and brown to ground.

Mehtab

Seats I got are from a 1993 sc400

Also you need to connect grey wire to positive

Post a photo for your connection so I can assist you

emoylv

No, that won't help me. There is no gray wire on the 2006 SC430 harness. Looking at the female connector on the passenger seat across the top from left to right, pin 1 is blank, pin 2 is blue/red, pin 3 is blue/white, pin 4 is pink/black, pin 5 is green, pin 6 is blank, pin 7 is blue and pin 8 is brown. Bottom row pin 9 is light green, pins 10 and 11 are blank, pin 12 is blue/yellow and pin 13 is white/black. Pins 2, 4, 5 and 8 go to the seat ECU. Pins 3, 7, 12 and 13 go to a 4-pin plug. Also, the blue/white, light green and white/black wires are a thicker gauge. There is no grey wire.