Installing Sheel-Mann seat heater on LX 450 (1 Viewer)

[BlackMud]

I personally wired my Scheel-Mann seat heater elements directly into the OEM seat heater circuit. I did it the same way as Toyota - elements are in parallel (12v) when on high and series (6v) on low.

The OEM circuit is rated for 20A and also includes the rear heat. Since my rear heat is disconnected, I swapped the 20A fuse for a 15A fuse and haven't had any issue with blowing fuses with both seats on High for several hours. The seat heaters may be capable of 15A per seat but I'm certainly not seeing that in practice...

Yes, I thought about doing that too. However, I have to check under the gear shift console if the LX comes with the front seat heater harness. After researching, it looks like most 80 series and a few LX450 came with the front heater harness. Not mine though, only the troubled rear heater was installed.

On the Lexus side, according to the depths of the internet the ones that came to the US had the front seats heater installed through the dealership. Someone correct me here if I’m wrong.

If mine has the harness for the front heater, I’ll definitely use it. The Sheel-Mann runs 15A per seat and their relay can run up to 40A. Knowing that the OEM circuit runs 20A helps a lot. Thanks for that info.

 

[BlackMud]

Here are some pics of Toyota relay assemblies I installed on my truck and a spare that doubles as a battery hold down.

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Nice, thanks for sharing the pics. Where did you get the extra relays?

 

[canman]

Yes, I thought about doing that too. However, I have to check under the gear shift console if the LX comes with the front seat heater harness. After researching, it looks like most 80 series and a few LX450 came with the front heater harness. Not mine though, only the troubled rear heater was installed.

On the Lexus side, according to the depths of the internet the ones that came to the US had the front seats heater installed through the dealership. Someone correct me here if I’m wrong.

If mine has the harness for the front heater, I’ll definitely use it. The Sheel-Mann runs 15A per seat and their relay can run up to 40A. Knowing that the OEM circuit runs 20A helps a lot. Thanks for that info.

The NA vehicles did not come with the seat heat wiring harness. Supposedly, all the LXs sold in Canada (96-97) had heated front seats and lockers as “standard” equipment. As mentioned, my LX came with “factory” heated seats, but they were “dealer” installed. The wiring in my LX for the heated seats is definitely not factory.

 

[canman]

Nice, thanks for sharing the pics. Where did you get the extra relays?

I picked them up at the wreckers over the years.

 

[Dr Gil]

I personally wired my Scheel-Mann seat heater elements directly into the OEM seat heater circuit. I did it the same way as Toyota - elements are in parallel (12v) when on high and series (6v) on low.

The OEM circuit is rated for 20A and also includes the rear heat. Since my rear heat is disconnected, I swapped the 20A fuse for a 15A fuse and haven't had any issue with blowing fuses with both seats on High for several hours. The seat heaters may be capable of 15A per seat but I'm certainly not seeing that in practice...

@haulin auss your Inbox is full so I'm hoping you see this message.

I have a 96 Land Cruiser with the factory seat heater pigtails under the center console and have the factory seat
heater switches. I have the OEM seat heater switches connected to the pigtails.

How do I delete the SM High/low/off round switch and use the factory switches?
Can you send me a picture of how you wired up yours?
According to your post, you didn't use the OEM seat heater switches you wired it to the seat heater circuit.
Would you be able to diagram to me how to wire up those SM heaters to the OEM switches?

Gil

 

[haulin auss]

@haulin auss your Inbox is full so I'm hoping you see this message.

I have a 96 Land Cruiser with the factory seat heater pigtails under the center console and have the factory seat
heater switches. I have the OEM seat heater switches connected to the pigtails.

How do I delete the SM High/low/off round switch and use the factory switches?
Can you send me a picture of how you wired up yours?
According to your post, you didn't use the OEM seat heater switches you wired it to the seat heater circuit.
Would you be able to diagram to me how to wire up those SM heaters to the OEM switches?

Gil

I used OEM Toyota switches plugged into the factory circuit, and then wired the two heating elements per SM seat into the factory OEM seat plug. This is wired identically to how Toyota did it, just using SM heating elements instead of Toyota.

You can cut the plug off the old seats and just use that to spice into the SM seat heaters, or replace the OEM plugs with a 3-pin Deutsch connector like I did. Lots of ways to skin that cat…

I used the EWD to figure out my wiring because I don’t trust relying on the internet for things that could burn my truck to the ground. I recommend downloading the free PDF copy available on this site, it’s a pretty simple circuit. Page 9 of this thread also has all of required wiring detailed, but I recommend double checking their work - 97' FZJ80 heated seat install with Toyota horizontal low/high switches - https://forum.ih8mud.com/threads/97-fzj80-heated-seat-install-with-toyota-horizontal-low-high-switches.899423/page-9