Here's a quick how to on wiring your heated seats using the factory wiring in the truck and the JDM heated seat switches. I originally made my own harness with relays and such, but this is a much cleaner and simpler install. Thanks to CycloSteve for sharing his wiring layout with me, saving me from hours of "quality time" with my multimeter!
Under the centre console of my 96 LC (and most others I presume) are these plugs:
(I bought new carpet from gotmud this summer, so it looks a lot nicer in there now!)
Left seat heater switch plug
Right seat heater switch plug
These are the JDM seat heater switches (photo courtesy of mot). Note that the connectors here are a perfect match to the connectors under the centre console, almost like Toyota knew what they were doing
If you haven't ordered a set of heated seat elements yet there are a couple good sources listed on the board. AATLAS1X is a vendor here and sells them
here. There was also a
group buy a few years back, and last I heard they were still honoring the discount price. TomH did a great writeup on installing the elements
here. I have a set from the group buy and IIRC CycloSteve's are from Shane (AATLAS1X), but the wiring on the kits is exactly the same from what I could tell. I wired mine the same way Steve did his, and neither of us has caught fire yet
I don't have any photos of this part, but if you take a look at the truck side of the electrical harness under your power seats you will see two pins that don't have corresponding wires on the seat side of the harness. These are the HI and LO power wires for the heated seats that come from the switches. Steve has explained which wires do what, but I second his advice to double check it with a multimeter first in case Mr. T changed wire colours at some point.
Following more of Steve's advice, I wired the yellow wire from the heated seat element control box to the 12V LO signal; the black wire from the control box to 12V HI signal; and the red wire goes from the control box to the ground on the power seat harness. I used some OEM wire splices I had kicking around to get the HI and LO signals from the seat connector to the heater element control box, and cut/spliced the ground wire into the ground for the power seats. This way you can still disconnect the plug and remove the seats without redoing any wiring.
The last thing I did was switch out the JDM switch body for the oak ones from a 92-96 ES300. The plugs on the back of the switch body are exactly the same, and I compared the wiring diagrams just to be safe.
I like the look of the oak switches in the oak interior. There might be a grey option out there too for those of you with the drab elephant skin interior
A couple other threads with some good info:
https://forum.ih8mud.com/80-series-tech/244742-looking-group-buy-heated-seats-last-year.html
https://forum.ih8mud.com/80-series-tech/254870-heated-seats-way-question-switch.html
Hope that helps!
