Go to volvodiag.com to view/download wiring diagrams 2005-2014.
4/52 uses CAN wires for probably memory function or codes, don't know.
Add power to 74/30 pin 1 Red wire and pin 2 Red/White wire.
Ground 74/30 pin 2 black wire and see if the seat works. The seat heater will probably not work w/o modifications. Pass seat does not use CAN logic.

mo

 

Thank you very much! I'll report back with my findings.

Do you happen to know even the color of the connector used for the airbag? Maybe I'm being paranoid I'd like to remove that entirely and cap off the wires.

 

Here is the SRS wiring for your seats. 8/92 and 8/93 should no longer be installed on your seats. Recall R10029 was to remove both 8/92 and 9/93 and install a resistor in its place so that the SRS message would not turn on. SIPS bag 8/51 and 8/52 are built into the outside edge of each seat. 3/93, 3/94 are the seat belt buckle. They tell the SRS brain what seat belts are in use. 3/255, 3/256 are seat position sensors.
You are probably safe in leaving 8/51 and 8/52 Seat SIPS bag alone. The last page is wiring color codes.

 

Here is the SRS wiring for your seats. 8/92 and 8/93 should no longer be installed on your seats. Recall R10029 was to remove both 8/92 and 9/93 and install a resistor in its place so that the SRS message would not turn on. SIPS bag 8/51 and 8/52 are built into the outside edge of each seat. 3/93, 3/94 are the seat belt buckle. They tell the SRS brain what seat belts are in use. 3/255, 3/256 are seat position sensors.
You are probably safe in leaving 8/51 and 8/52 Seat SIPS bag alone. The last page is wiring color codes.

Thank you again. You really are "Volvo God"!

Crazy how complex everything is on a car today. I wouldn't figure to try to remove the actual 8/51 & 8/52 devices, only the wiring ends/connectors. Given that I'll be custom wiring things, I just want to eliminate any chance that I could hook things up wrong. I'm pretty detail-conscious, but we've all done something stupid at one time or another.

 

My blog might help, I made some into desk chairs. Misc. Project - Volvo P3 Desk Chair — NordCarolina

There are essentially 2 12v power wires and a ground, literally everything else in the big connector is for the airbags and safety equipt.

 

^^^ Super helpful - thank you! I see you left the Occupant Control Module (p/n 1319520) in place. Just because, "Why bother taking it out?" I'd assume you also left the Occupant sensor in place (p/n 12228430).

Mine also has the Heated Seat Control Module (p/n 31268907), which may explain why a couple of the wire colors don't match at connector 74/31. I'll leave that in place for now in case I try to tackle getting the heated seats to work.

 

Got the seat movement fully working today on the passenger seat. I'm sure the driver side will be the same. Indeed all you need are the three wires. As you can see, I've removed everything else. I also removed some of the airbag sub-harness, the Occupant Control Module, and the Occupant sensor.

Now I'll move onto trying to figure out the heater.

 

Moving on to the seat heater circuit, I see that circuits 1, 2, & 4 (connector 74/30 & 74/31), control those. Certainly I can add those back in - you can see in the pic above that I already removed them. Or, I may want to go further upstream and remove more of the complexity in this circuit. Basically, I would just want to have a simple two-wire (12V+ & Gnd) setup with an on/off switch. I'd want to throw a relay on the circuit, but I can sort that out later. Thoughts on how to best do that? Circuit #1 is Gnd, that seems obvious. Do I need to feed #2 AND #4 with 12V+ or can it just go to one of them?

 

Looking at page 159 of the factory schematics...
https://drive.google.com/file/d/1Z7CFVF ... Y9HNE/view

I've confirmed that it's three circuits (1,2, & 4) coming in through connector 74/30 (74/31 on driver side) that are involved with the heater. These three wires go to a Heated Seat Control Module (p/n 31268907) and then go out from there via a 2-wire bundle and a 4-wire bundle. I'm a little stuck right now trying to sort through that. Ideally I would just eliminate the control module and splice the wires in to send 12V out to the two (?) heating pads. I'll control the 12V via an upstream switch.

Any thoughts?

 

Looking at page 159 of the factory schematics...
https://drive.google.com/file/d/1Z7CFVF ... Y9HNE/view

I've confirmed that it's three circuits (1,2, & 4) coming in through connector 74/30 (74/31 on driver side) that are involved with the heater. These three wires go to a Heated Seat Control Module (p/n 31268907) and then go out from there via a 3-wire bundle and a 4-wire bundle. I'm a little stuck right now trying to sort through that. Ideally I would just eliminate the control module and splice the wires in to send 12V out to the two (?) heating pads. I'll control the 12V via an upstream switch.

Any thoughts?

Okay, here's what I'm thinking.... I just ignore (remove) circuit #4. I'm not sure what it does, but I'm thinking (hoping?) I don't need it and can just eliminate entirely. Then I've just got to provide 12V+ to circuit #2 and Gnd to circuit #1. Then, the challenge is sorting out those two connectors at the control module. I'm assuming one goes to the bottom and the other to the back seating pad. But why does one have 2 wires and the other 4? Never mind, I'm seeing now that the two extra thin-gauge wires (both yellow) go to 7/110. What is that? Can I just ignore?

Otherwise 9/16 and 9/18 must be the two heating pads with a simple + and - circuits. Does polarity matter on those?

 

Forging ahead, I went ahead with some tests, first directly putting 12V+ and Gnd to the two circuits (C-1 & C-2) in 9/16. Nothing. I'm now thinking this doesn't even go to the pad circuit.

Then I moved on to 9/18, the green quick-connector, putting 12V+ and Gnd to B-1 and B-4. It worked - the seat bottom gets warm, but I did notice that after five minutes the green connector and wires got (too) hot to the touch. I would have been okay with just needing to turn the heater off if the seat got too hot, but not at the risk of burning the car down.

The Ford OEM approach on the original seat is to give 12V to the circuit and use a thermostatic switch in the pad to cycle the circuit off and on as certain temperature thresholds are reached. I suspect that's not a good enough solution here. The Volvo heater pad doesn't want to ever see a full 12V I'm thinking. Maybe there's a low-tech solution where I can just put an in-line VR in the circuit?

On a related note, is there only a heater pad in the seat bottom and not the back? That's what I'm thinking now as I don't seem to see any wires running to the back.

 

I might be the only one on the planet trying to figure out how to make a seat heater work while it's 94 degrees out! But I digress... I've been researching since the last post, and it seems it's really amperage draw I need to work with. Any and all input appreciated. I'm on the edge of my electronics knowledge, but no need to be nice if I've made any bad conclusions.

From what I'm reading, typical amperage draw is no more than 5A per seat. I already have a set of on/of switches and harness from the PartScorpio, So maybe one of these tucked away for each seat....
DC Motor Speed Controller: 12-40V 10A PWM Motor Speed Control Switch Controller with Voltage Regulator and Dimmer

Dc Motor Speed Controller 12 40v 10a Pwm Motor Speed Control - Temu

Or, better yet, for the same price ($3.50), this one is good for 20A and the rheostat is remotely mounted...
1200W High-Power DC Motor Speed Controller - 20A PWM Regulator with Wide 10-60V Input, Advanced Control & Built-in Safety Fuse for Unmatched Performance

Dc 10 60v 20a Dc Motor Speed Controller Pulse Width - Temu

 

In case anyone is still following this, I went ahead and ordered a couple of the 20A PWM controllers as pictured directly above. Wired one in tonight and I have functional variable seat heaters!

 

I had no idea that a company like Planted Technology existed. It won't help me on this project (no Merkur plate), but it could for some other project in the future.

I'm pretty sure I just have a heater in the seat bottom and nothing in the back - no heater and/or fan.

The only concern I have with my rheostat is whether it's okay to leave fully cranked up for an extended time. Since it's somewhat hidden away I would figure to just leave it set about mid-way all the time any way, but what if something get stuffed under the seat and accidentally turns it to max? This probably won't happen, and might not be an issue regardless, but I always try to make my solutions idiot-proof.

 

You should find the setting that you are comfortable with leaving as your max setting, measure the resistance of the rheostat at that value and then put 1/4 watt resistors in place of the rheostat. Assuming of course that you have enough room on board the circuit for the resistors to live safely.

Good job BTW. I've got a 2013 S60 that I just pulled the powerplant from. I am going to pull the seats too now and save try to put them in my 245.

I wish mine were black but I guess I can put covers over the seats now that I will be disabling the airbags.

Id like to recover them but I've got waaaayyyy too many irons in the fire right now.

 

Great read! I also have some spare S60 seats so this is a great thread for me! Kudos to you!

 

Finally got back to this project. The physical fitment was way more difficult than I imagined, mostly because of the 19" width (O.D.) of the seat tracks. The driver side is pretty much done as well - I just wanted to run the passenger side through it's paces for awhile to make sure there aren't any unexpected issues. Thanks to all who helped make this happen.