Hey guys, my ‘03 was in dire need of a full interior upgrade, and I scored everything I needed from an 09 at the local yard. Of course the seats bolted up just fine, but the wiring harnesses are totally different. Not only the connectors, but the color and number of wires per connector. Before tossing the old seats, I took their harnesses so I could reuse the connectors to the trucks harness. Does anyone have wiring diagrams for both these years? Or is there a write up anywhere? I’ve been searching for about an hour, but couldn’t find it. Both year seats are non-powered driver/passenger with the exception of lower lumbar support on the driver side. Any help would be greatly appreciated, thanks

Following. Will look thru our files for wiring diagram.

Toyota Factory Service and Repair Manual - 2007 4Runner + Updates
Scroll down to the E.W.D section for the wiring diagrams. This is for an 07, but it will be the same for the 09.
And here's the 03 diagrams.
2003 Toyota 4Runner Electrical Wiring Diagram (EWD514U) | Free Download

I put some seats from an 06 in my 03. They were manual seats so it makes to process pretty easy.

-Just leave all the plugs on your 09 seats alone, take the buckles off of your 03 seats and put them on the 09 seats, plug them in to 03 plug.

-Unplug the lumbar wires off of the 09 lumbar motor, follow the wires up the seat back, and plug in the 03 to the lumbar motor, the plug on the motor is the same.

-The driver side is done at this point, the passenger seat you need to remove the weight sensor from the foam and stick it in between the foam and cover of the 09 seats, just plug it in to the 03 plug in the floor.

I looked up how to actually wire these in, and its a nightmare due to differences in airbag stuff due to the way the weight sensor is set up in 06-09 passenger seats...

***If they are power seats just wire them up with 12v to pins that are needed for seat power and then follow the process above

-If you want pictures ill get them to you

Circling back to this, I appreciate the help so far. Unfortunately I tossed the old seats while cleaning out the garage. I did snag the 06-09 truck harness connectors if that’s any help. I’d rather wire these in so they appear OEM, I don’t want to pull the seats apart and mess with the upholstery. Is there anyone else who has rewired 06-09 seats to the factory 03-05 truck harness? When it’s complete, will I need to run it by Toyota to have the airbag light reset? Thanks in advance

I went through this with my '03. My driver's side seat was worn and someone listed a brand new 2005 seat on CL. I ended up removing the '03 seat, putting them both onto a work bench and completely transferred the '03 harness over to the '05.

It's not hard to do, but does take a couple of hours. The '05 seat has an airbag in it, but my '03 didn't have that plug...just left it alone and connected up the rest of the harness.

If you threw out your old seat, well that's going to suck. The plugs on the '05 don't match to your interior harness. Good luck!

Go hit up a pull-apart... buy some trashed 03-05 seats. Thats all i can offer. The 06-09 seats will probably never be able to wired in correctly, the airbag ECU and seat weight sensors are completely completely different... Just do the steps i mentioned above.

My brother is an electrical engineer, He looked over the wiring diagrams and basically told me it was impossible, but i wish you luck.....

It’s just the passenger weight sensor that’s the issue if I got 03-05 seatbelts? Guess if it’s that impossible then I’ll have to disassemble it. We have a local yard with 10+ 4runners, I’ll have to run by

You also have to use the sliding track off of the 03-05 drivers seat. Just unbolt the torx bolts and attach the 06+ seat to the 03-05 base. There is a sensor on the sliding track that adjusts how the airbag inflates based on the seat position. You need this and it's different on the 06+ seats. I think this part slipped my mind in previous posts...

Hey, can you do me a solid and post a link for the wiring diagram for a 2005 V8 4x?
Thanks

What yard around C. Tx has 10+ 4th gens in it?? I've only found a few lol.

Late Model Wrench A Part in Holland Texas has like 10 or more!

Word! Thanks!

2003 Toyota 4Runner Diagram.

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2009 Toyota 4Runner Diagram.

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