chrushw

Hello,

Looking for some help ...

I am trying to retrofit heated seats into my 2000 RX300, which originally came without the seat heaters.

Here's what's been done:
1. Replaced front seats with a pair that has the heating elements in them. Continuity check (per a technical bulletin) indicates that the elements are OK. Connected the seats to the wiring harnesses.
2. Installed switches in the dash. Continuity checks (per a technical bulletin) indicates the switches are working correctly.
3. Plugged the switches into the wiring harness using the connectors already there.
4. Installed the Seat Heater Relay in the lower right foot panel.
5. Checked the fuse provided for the seat heaters - it's OK.

When I press the driver's seat switch, there's no indicator light, and no heat. The passenger switch indicator light comes on, but no heat either.

Does anyone know what else needs to be connected to make these work?

Walt

salimshah

Walt:

You can not rely on the wiring harness to have the actual wires you need for an accessory that did not come with the vehicle. You have to check actual voltage on the connector(s).

Salim

chrushw

Salim -

I suspect you are correct. According to the parts fiche info, some models came with a complete harness even though heated seats were not originally included. I was hoping mine was one of them. Guess I'll have to chase through a wiring diagram.

Your reply is sincerely appreciated,

Walt

chrushw

OK - I was able to get both front heated seats working. I thought I would post a summary of everything that is involved. The wiring diagram manual is a necessity to get everything correct, as it's a good idea to do some continuity checking as you go along. Here's a summary of what components are needed to retrofit the original heated seats in a 2000 RX300:

1. Driver & Passenger Seats with original heating elements.
2. Driver & Passenger Seat Heater Switches. For the 2000 model, they are single position ON-OFF switches. The connectors are located directly forward of the switches - for vehicles that did not originally come with heated seats, the connectors and wiring were tied out of the way with cable ties.
3. Seat Heater Relay for the Passenger Seat. It is located under the plastic cover next to the passenger's right foot.
4. The Seat Heater Relay for the Driver's seat which, for some reason, is called the "Engine Main Relay". It is located next to the fuse panel behind the coin box on the driver's side. To access the area, the plastic cover beneath the steering wheel must be removed.
5. There is a 15A fuse for the seat heaters located in the fuse panel on the driver's side. My vehicle came with the fuse already in place.
6. Almost all of the necessary wiring is already in place. The only connection missing is the feed from the Passenger's Realy to the Passenger's seat. I elected to splice a wire behind the relay terminal, and run it under the carpet and splice it behind the connector which plugs into the seat.

Total cost was $250 for the seats, $20 for the switches, and $80 each for the relays. And $35 for the wiring manual. Now I have the original (non-heated) seats to sell to recoup some of the money.

The whole process was fairly easy. If anyone wants to give it a try, please feel free to contact me for more specifics.

WALT

trhs75

Walt --
Congratulations! I've got to try to replace both existing heating elements (or the entire seat) on the driver's side of our RX. The wiring is there, of course. I've toyed with the idea of seats from a recycler, but I was concerned about winding up with non-working heaters again. Plus, I don't look forward to disassembling and re-upholstering. Did you find some nice recycled seats somewhere?

chrushw

Yes,

I bought a pair of front seats off of eBay last year, from a seller who had very good feedback. As for checking the heating elements, all you can do is a continuity check from the connector under the seat - pin 11 (green w/red stripe) to pin 16 (white w/black stripe).

If the resistance is near zero, the element is probably good.

Walt C.

trhs75

That should be helpful. Thanks for the tip, Crushw!

cherokeech

wow
thanks for the info!
im trying to set up a set ofr these seats in my old jeep and i thought all i had to do was wire the 2 heater wires to ground and hot.i guess there is a lot more involved.i got the switch lite to work but thats it.im only using 2 wires from the main connector for the motors to work.any ideas on how i might be able to get this setup to work on my jeep?if its too involved ill just scrap the idea.im happy enough that i finally got them moving!

cherokeech

also whats up with the lighted switch?should it be hooked up to ign hot only so if you forget the heater wont drain the battery?

cherokeech

switching the 2 wires did nothing.maybe they are both hots and it grounds from somewhere else?

chrushw

Cherokeech,

Installing the RX300 heated seats in another vehicle should work, unless the heating elements are burned out. You should check for continuity between pins 11 and 16 in the connectors. On my 2000 RX300, the driver's seat #11 is a Green wire with Black stripe, the passenger's seat #11 is Green with Red stripe. For both seats, #16 is White with Black stripe.

If those are OK, what you have to do with a heavy duty switch, or a light duty switch triggering a relay, is send +12 volts to pin #11 of the seat connector, and connect pin #16 to ground.

Are you trying to use the RX300 switches too? They're wired kind of funny, and it's possible for the light to come on but no power going to the seat heater.

Erik

I had aftermarket seat heaters added to my '99 years ago. It was around 400 installed, I could have done it myself for around $120 a seat. My only mistake was putting in non-lighted switches. I have 2 level seat heaters and I had the switches put in the normal location but there is no light to indicate they are on. They turn off with the ignition so its not a big deal.

cherokeech

hanks guys

yes i was trying to use the factory heated switches and i see they are wired kinda funny.what you are saying is that im gonna have to use a wire from the big connector as well correct?the 2 heater wires are red and black and i thought i could just give the power to the red and ground the black one.like u said the lite comes on but no heat.im gonna try to read this all again and give it another shot.thank you guys so much for the info!

mark
76 cherokee chief
502 chevy,dana 60,14 bolt.turbo 400,np205
42 inch swampers and lexus seats!,my daily driver

RX300Russ

Walt - where did you get the wiring diagram?

chrushw

The parts counter at the Lexus dealer was kind enough to make copies of several pages from the official wiring manual. But since I wasn't sure where the relays were located (therefore which pages I actually needed copies of) I wound up buying the electrical manual off of eBay - for $35. If you have specific questions, please let me know and I'll try to help.

Retrofitting the original Lexus configuration wasn't that hard - if you can find a pair of original heated seats in good condition.

Walt