Seat Wiring Diagrams

[Extremneon]

Hello,

installing PRP seats in my Jeep JL with the heating elements. Does anybody know which wire in the harness is the power and ground for the OEM heating elements in the seat. I am hoping to splice into them to power the aftermarket elements in the PRP seats.

thanks.

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[Extremneon]

I found what I was looking for through a Google search and looking at all the Jeep JL electrical connections and figured I would share for others.

now let’s see if I can make aftermarket seat heating elements work with the OEM connections.

 

[Extremneon]

Does anybody know how to trick the system in the JL with the four wires going to the stock heating pads.

The OEM connector it a supply, sensor return, temp sense and ground. The aftermarket is just two wires, power and ground wire.

When I try to just plug the power (Aftermarket Heating Element)to the supply wire (OEM Connector) and the ground (aftermarket Heating Element) to the ground (ORM Connector) and push the button, the seat heater light on the dash comes on and then quickly goes back off. I tried to connect the temp sense to the return wire directly and it does the samething, no difference.

it obviously has something to do temp sense and return wire or something I am missing here.

 

[BigMaCro]

I don't think it's practical to get it work with the factory switch.

Here's the wiring diagram for others to see, though it sounds like you already looked at it:

https://www.jlwranglerforums.com/JL-Wiring-Diagrams/HEATED-SEAT-SYSTEM.pdf

What many folks aren't used to yet, is that all the wiring in these new cars, including our beloved JL, is connected not to a basic switch run to the battery, but to computers. The wiring from the heated seats and wheel connect to the "Comfort Seat Steering Wheel" Module, which reads the temp sensors for the seats and modulates the heating accordingly.

This module is controlled over the CAN bus (network linking all the computer modules together). When you hit the switch, the center stack module sends a message over the network that you'd like to turn on heat. If the right conditions are met, the seat/wheel module will heat the seats.

The module will be watching for the proper voltages from the temp sensors as well as watching the current on the heating pad, to ensure everything is working as designed. If these measurements are out of spec, it'll error out and disengage. So sure it would be possible to design an aftermarket heated seat that was compatible, but it would take a bit of work.

 

[Extremneon]

I don't think it's practical to get it work with the factory switch.

Here's the wiring diagram for others to see, though it sounds like you already looked at it:

https://www.jlwranglerforums.com/JL-Wiring-Diagrams/HEATED-SEAT-SYSTEM.pdf

What many folks aren't used to yet, is that all the wiring in these new cars, including our beloved JL, is connected not to a basic switch run to the battery, but to computers. The wiring from the heated seats and wheel connect to the "Comfort Seat Steering Wheel" Module, which reads the temp sensors for the seats and modulates the heating accordingly.

This module is controlled over the CAN bus (network linking all the computer modules together). When you hit the switch, the center stack module sends a message over the network that you'd like to turn on heat. If the right conditions are met, the seat/wheel module will heat the seats.

The module will be watching for the proper voltages from the temp sensors as well as watching the current on the heating pad, to ensure everything is working as designed. If these measurements are out of spec, it'll error out and disengage. So sure it would be possible to design an aftermarket heated seat that was compatible, but it would take a bit of work.

That is kinda what I was afraid of and not see this mod done yet in success in the JL.

I guess the other option would be to buy the stock OEM heating pads and install them in the PRP seats so it will read properly with the module and turn on and work. I was honestly was hoping to a void this and didn’t want to have remove the covers off brand new seats.

Or I can use the wiring and switches that came with the PRP seat and mount new switches in the center console, that would probably be the easiest method. I did run the aftermarket heating element power wire to the OEM harness in the ACC/SWITCH wire and worked perfectly.

 

[BigMaCro]

So maybe, just maybe, if you measured the resistance of the OEM sensors when they're cold, and built a jumper with an equivalent resistor, you could fake it out. Do your seats have two pads each? I think the module would error if only one heating element was present - although then you could maybe wire both seat and back supplies together. Do you mind potentially frying the module that also controls your heated wheel? ;-)

 

[azjl#3]

or maybe buy just the oem heated seat element? I am not sure they sell just that.

My thought with all these computer controlled vehicles, buy oem, you'll save time and money. And won't fry your stock stuff.

If you want you can run a dedicated circuit from the battery to your aftermarket stuff, but that would be more trouble than oem imo.

 

[Extremneon]

Each seat has two separate pads, one for the back rest and one for the cushion. Each pad has a connector with four wires that has individual connectors that then leads to the main connector underneath the seat.

You definitely can buy the OEM heating pads for the seats, I think there are approximately $200 for them and they then would just hopefully work, those than the pain of removing the covers from both seats.

I might look at the stock seats and see if I can measure the resistance in the stock heating pads and see maybe if I can trick the module in thinking they are hooked up with resistors, worth a try.

 

[Extremneon]

I checked the ohm reading for each heating element at cold conditions. Both the seat back and cushion read close to each other in the 21. range.

The air bag connectors read at 2.2 on the seat connection and the belt tensioner and retractor also read the samething. I have three of them per seat I need to deal with to get the dash light to go away.

 

[Extremneon]

Might buy some 22 ohm resistor and give it try on the temp sense and return wires on the heating pad connectors.

 

[Budgetglady]

Might buy some 22 ohm resistor and give it try on the temp sense and return wires on the heating pad connectors.

Did the 22 ohm resistors work??? Looking to do this currently.

 

[Extremneon]

Did the 22 ohm resistors work??? Looking to do this currently.

No, I couldn’t figure way to keep the lights off the dash. I constantly get the seat belt reminder every time I come to complete stop and start to move again and the air bag light is on.

The seat heaters also had to have separate switches for all fours seats.

 

[amyinthedesert]

I know that this is an old thread, but I’m wondering if there is a way to add heated seats on my 2021 Sahara 4XE that didn’t come with them. Can the dashboard be replaced to have OEM switches and have the wires hook up to a replacement faceplate (I’m sure they must make them?)? I’d really like it to look like the Jeep came with them. I had a 2013 Jk and my ex put the switches on either side of the dash (looked kinda silly, imo, but it worked).
Now that we’re divorced after 30 years of marriage, he’s no longer an option to even ask. Too much hurt for me to ask him about the weather let alone my Jeep. TIA.

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