97' FZJ80 heated seat install with Toyota horizontal low/high switches

[jwilliams]

I'm glad this thread resurfaced. I looked for those upper/lower pads years ago, and couldn't find anyone selling them. This made me look again, after seeing what LCH wanted for them, and realizing that if they truly were reselling OEM pads, they must be available again. Sure enough, McGeorge has them listed (both) for less than LCH wants for the pair of lowers (that they won't sell separately).
Pad, LF, seat back:
View attachment 3353999
Pad, LF, seat bottom:
View attachment 3353996

Pull the trigger on the new foam for seat and back on both front seats, it is a world of difference! I did it when I did this heated seat project.

 

[thetoyotaman]

Has anyone had a problem with the stock 20A fuse overheating and blowing after a while with the aftermarket seat heaters?

 

[fj40ingkc]

Has anyone had a problem with the stock 20A fuse overheating and blowing after a while with the aftermarket seat heaters?

I did blow one fuse under the seat, closest to the heating element. Likely due to me not disconnecting battery when adjusting wiring. Have not blown one since.

 

[residualboulders]

Odd behavior all of a sudden on my driver’s seat heater wiring - I bought the truck with this mod already done and everything worked like it should.

Out of the blue, I started getting some Hi/orange illumination when Lo/green is selected on the LH/Driver’s seat only. Swapped the switches and it doesn’t follow the switch. This leads me to believe there is a small short, likely under my seat and unrelated to the switch, pigtails, or their extension solder joints.

I’ve separated all of the pigtail wiring and I still get this “backfeed” situation you described.

Could you help me understand what you did incorrectly the first time so I can more quickly chase down the wonky wiring?

The other odd thing is sometimes the Lo wouldn’t illuminate at all - unless I cycled on the rear heater. I don’t see any janky splices under the console harness, so not sure how one has any effect on the other.

Current situation. Driver’s side is acting up and passenger side works as expected. I checked under each seat and the wiring looks exactly the same.
View attachment 3336657

I’m getting this too, haven’t figured it out yet.

 

[Malleus]

How much aftermarket stuff is wired into the body harness? That fuse will not blow if the circuit is OEM; there's not enough current draw. For example, the Rostra 250-1900 seat heaters I installed recently only draw 4A each. Of course, this is only if they are installed correctly.

 

[Malleus]

 

[ColoradoLC]

I'm trying to unravel something with the instructions at the top, and maybe I'm missing something, so I'm going to post the sections and what I am misunderstanding.

I have my seat heater switched (vertical) in and connected...no problem there.

WHERE TO ADD THE PINS UNDER THE SEAT FOR POWER TO THE HEATED SEAT ELEMENTS
Here is picture showing the underside of my seat. I noted where the seat bottom element wires come through and the seat back wires come through. You join those together and then attach Toyota male pins to the positive HIGH and positive LOW wires. I had some old wiring laying around that I could use for the pins, so you will have to find some or source them from somewhere. You will need four of them ( a positive HIGH and positive LOW for each seat.
But here is a picture of what one would look like so you can get an idea:
View attachment 1179335

Here is a picture of the underside of the seat with notes on where and what is going on:
View attachment 1181428

The overall wiring scheme boils down to this at the existing connector (floorboard-side) under the seat.

White with black trace = Ground - you will need to tap into this one, as it is also used for the powered seats.

Blue with black trace = +12v when you have the OEM/JDM switch in the Lo position

Blue with orange trace = +12v when you have the OEM/JDM switch in the Hi position.

Here is a close up picture of what it looks like and shows the ground wire being tapped into:
The two green wires you see on the left are the positive HIGH and positive LOW that I added.
View attachment 1179338

In my undertseat connector I do have a blue wire with a black trace, on both the floorboard side as well as the seat side. If the blue with black trace already exists on both side of the connector, am I not adding a pin for the +LOW heat setting?

Ground - The instructions indicate to tap into the white wire with black trace, but I am not seeing where that goes? My heating elements have a red wire and a black wire coming out of them (these are the carbon seat heaters that Land Cruiser Heaven sells). Some of the instructions don't say anything about a ground and some do, which seems to be a discrepancy.

I have the blue wire with orange trace going to my red wire for both seat heaters (back and bottom of one seat). This part I am confident in.

I am sure this won't work if I don't understand what I tap into the ground for. The underseat pictures from above only show two wires coming out of each seat element, a +HIGH and +LOW heat wire.

What am I missing?

 

[ColoradoLC]

I'm trying to unravel something with the instructions at the top, and maybe I'm missing something, so I'm going to post the sections and what I am misunderstanding.

I have my seat heater switched (vertical) in and connected...no problem there.

The overall wiring scheme boils down to this at the existing connector (floorboard-side) under the seat.

In my undertseat connector I do have a blue wire with a black trace, on both the floorboard side as well as the seat side. If the blue with black trace already exists on both side of the connector, am I not adding a pin for the +LOW heat setting?

Ground - The instructions indicate to tap into the white wire with black trace, but I am not seeing where that goes? My heating elements have a red wire and a black wire coming out of them (these are the carbon seat heaters that Land Cruiser Heaven sells). Some of the instructions don't say anything about a ground and some do, which seems to be a discrepancy.

I have the blue wire with orange trace going to my red wire for both seat heaters (back and bottom of one seat). This part I am confident in.

I am sure this won't work if I don't understand what I tap into the ground for. The underseat pictures from above only show two wires coming out of each seat element, a +HIGH and +LOW heat wire.

What am I missing?

Update on this question I asked, which was answered later in this thread, but not in the initial few posts. I'm posting this in case anyone that comes upon this thread later will get the answers I was looking for.

For the seat heating pads that I bought from Frank at Land Cruiser Heaven, there were two wires coming out of each pad. I cut out the rest of the wiring harness that came with these to use the red and black wire coming out of each pad along with the OEM vertical seat heater switches.

Figure 1: My wiring diagram of seat heaters (1 and 2 for back man butt heaters) to female end of connector under the seats:

Figure 2: Photo of my underseat connector. I used yellow for the LOW+ power and red for HIGH+ power:

In spite of my wiring drawing having 4 boxes, only one side of the connector has 4 connection holes and these are White (ground), my yellow (LOW+), red (HIGH+) and blank.

1. Tap into the ground and connect the other end to 1 black from one seat heater (it doesn't matter which).
2. Add the pin connected to your yellow wire to the second hole as described above. This will go to the black wire coming out of the other seat heater, making this connection an "In Series" connection.
3. Add the ping connected to your red wire to the third hole as described above and connect to to both red wires from the 2 seat heaters. This is "In Parallel".

Figure 3: Not the best picture, but it shows both red wires going into the red wire from the connector under the seat. The black wire you tapped into from the connector goes into one black wire and the yellow goes into the other one.

The final result is that my butt is toasty on winter days even on low, and now my wife will ride with me now that the seats aren't so cold.

The final product:

 

[residualboulders]

@jwilliams thank you for this excellent write up. My 97 still has the factory center console in it. I installed the vertical switches following your instructions and it went very smoothly and they work great.

My 1994 has a Delta VS center console so I decided I would get horizontal switches to install them on the dash. This is not as simple since my 94 does not have the heated seat plugs in the wiring harness like my 97 did. So I’m seeking help from all the knowledgeable folks on the mud forum.

I planned to use the relay that came with my aftermarket heated seat pads (since my 94 wiring harness was not prepped for them) and just replaced the switches with the oem horizontal switches.

So the Besond heated seat pads, have a switch for driver and passenger. The wires are as follows.

Driver:
Black
Red
Yellow
White

Passenger:
Black
Red
Yellow
Blue

Wiring harness has:
Red - Battery positive
Black - Battery negative
Yellow - dash lights
Red - ignition

All you fellas that are smarter than I am - how would you wire that up to the horizontal switch pin out below?

I’d like my switches to be able to be dimmed with all other dash lights, not sure how to do that. I can’t get any info from Besond on what the four wires for the switches do. I’m assuming Black is ground, red is high yellow is low and the white or blue is illumination, but I really don’t know. Any help would be appreciated.