heated seats conversion

[tomloans]

Hello all. I currently have the basic seat in my Z71. No Lumber and no heated seats. Only up and down and forward and back electric set up. Found some with lumbar and heated seats. ( my back cant take it unless I have some lumbar support ) Anyone have any idea how to wire up the heated seats so I have heat as well. After some research it appears to be quite an undertaking. Would love to hear from anyone who has accomplished this task. It looks like it will be a long winter. I have time on my hands.
I have an on off switch ready to go. I found the 3 wires for the seat heater. Two black and one blue. I just cant figure out what's what down there below the seat. I can bring power to the heat pads just don't know where to hook it up.

 

[krbjmpr]

Last time I had a heated seat brought to me, unknown model / year, I took advantage and poked around a bit for a project of my own.

There are 3 heat settings, High, Medium, and Low. You are putting current through both elements for High heat. This can get done by 12v being applied to both black, and Blue will be ground / return to battery negative. Medium will be putting power to blue / black wire pair that has lower resistance than the other blue / black pair. Low is putting power to blue / black pair that has greater resistance.

You are going to need a dual switch to use the 3 heat settings. With the elements being resistive elements, they can be powered from either end. Ground side switching has power coming in in your common wire (blue), and switched ground in black. While usable, elements would be powered all the time. Perhaps a better way would be to provide power through a switch to each black, and ground the blue.

I would suggest that you use a relay to control power, and use switch(es) for relay control via coil. Relays excel in switching heavy currents repeatedly. Switches can be rated, but quality varies. At the absolute minimum, I would still use a relay located before everything to be used as a master on/off. You would always have a way to shutoff heaters up switch goes sideways.

It is very easy to leave seats turned on and forget. May I suggest the use of a defroster relay / switch as a master? These typically have a fixed timer and will turn themselves off. Find them in vehicles that aren't 100% computer controlled and have defrost option. Look at 1990s suburbans...

Be mindful of total power draw vs wire size. You can measure resistance between blue and both blacks (together). For sake of math, let's assume 1 ohm. 12v / 1 ohm = 12Amps, and would need 14awg wire, half ohm is 12v / .5 = 24amps, needs 10awg, 2 ohms is 6 amps, etc.

Good luck and have fun.

 

[tomloans]

This is perfect and exactly what I was looking for. Thank you so much.

 

[krbjmpr]

Welcome.

Sent friend a message to see how his setup is holding up and what vehicle it was. Will update when replies.

 

[krbjmpr]

Heard back today. Truck is a heavy DIY Lightning, incomplete chassis F450 7.3L Navistar and had been rebuilt after essentially being totalled from cab fire. Originally equipped with bench in front and back, seats were replaced with captains in front, and full size slideout bench in rear. Has ambulance package, was a fire-support truck of some sort. Ironic.

Lot of interior is being taken from Expeditions or Excursions. I forget which. Driveline is stock and well worn out, plan is to drop in mill from a late 2000s medium duty International and utilize the auto-clutch and add propane injection. Conversion from dually to commercial "wide" in back.

In the meantime, electrical power is available to burn, and every creature comfort possible will be put on eventually including electric bed raise and chassis raise (!!??) for service.

Back to seats and warmers. Seats were reupholstered again, this time professionally with CatSkinz, and are now heated and cooled (perforated leather I assume). Apparently is drop in Upgrade if reupholstering. In addition, steering wheel will be heated as well. One more was mentioned that I don't understand. Hybrid air conditioner. No idea if that means if compressor will be electric.

I didn't understand half what I was told, but will be a head turner for sure. Kids have too much money these days.

 

[S33k3r]

Nice. I really want to add cooling to the seats in my Silverado.

 

[tomloans]

Heard back today. Truck is a heavy DIY Lightning, incomplete chassis F450 7.3L Navistar and had been rebuilt after essentially being totalled from cab fire. Originally equipped with bench in front and back, seats were replaced with captains in front, and full size slideout bench in rear. Has ambulance package, was a fire-support truck of some sort. Ironic.

Lot of interior is being taken from Expeditions or Excursions. I forget which. Driveline is stock and well worn out, plan is to drop in mill from a late 2000s medium duty International and utilize the auto-clutch and add propane injection. Conversion from dually to commercial "wide" in back.

In the meantime, electrical power is available to burn, and every creature comfort possible will be put on eventually including electric bed raise and chassis raise (!!??) for service.

Back to seats and warmers. Seats were reupholstered again, this time professionally with CatSkinz, and are now heated and cooled (perforated leather I assume). Apparently is drop in Upgrade if reupholstering. In addition, steering wheel will be heated as well. One more was mentioned that I don't understand. Hybrid air conditioner. No idea if that means if compressor will be electric.

I didn't understand half what I was told, but will be a head turner for sure. Kids have too much money these days.

Wow, some people have a lot of energy!