Reedearl

hello, I have a 96 LS400. The heated seats never worked since I purchased the car. I have read the old service receipts for this car and they say the dealer replace the heaters, some time in the past. I am thinking that they need to be replaced again, fuses are good and the switch lights up. Has anyone replace the seat heaters before?
Reedearl

Bali26

Theres also a few relays. Under the seat.

Och

iTrader: (3)

You can replace the heating elements but its a pain to do, because of how the leather is stiched, u will have to do a lot of work.

DoktorYes

check Seat Htr Fuse,engine main relay,seat heater switch,wire harness,seat heater.That's about all you can do, without getting the wiring & connector diagrams and a auto volt&ohm meter and getting busy.maybe someone on the forum can send you the wiring diagram.

Famou$LS

I have the same problem. Just a quick ?, we only have one fuse box and its under the hood, right??, I just got my 95 and i can't find a cabin fuse box

mkaye

i have had my '96 for 2 months, & now that it is cold, my wife tried the heater, but they don't seem to work
ReedEarl, did you find the problem?
do i need to track down a wiring diagram?
or just have a go with the meter?

mark

ryhi

iTrader: (1)

i got the same problem. only my passenger side heater works. the driver side one never worked since i got it and i never looked into fixing it beyond checking the fuse.

mkaye

anyone tried the aftermarket heaters?
i can get the heaters for $90 (seat & back) or $269 installed (1 seat)
i have the upholstery tool & clips from my mechanic & plan to tackle it myself, unless i get feedback telling me otherwise

mark

Kansas

There should be a lengthy but simple diagnostic procedure for the seat heater system in the repair manuals for your model year LS400.

My recommendation is to either obtain the repair manuals (ebay?) for your car or download the diagnostic instructions from Lexus techinfo by paying the $10 fee for 24 hours which will allow you to download lots of other stuff too.

All it takes to figure out seat heater problems is a multimeter and knowing how to use it and a trouble light for heating the seat heater thermostat -- should take less than 30 minutes to figure out exactly what the problem is ... beats guessing and blindly replacing parts.

mkaye

the heater is definitely open in the drivers seat
just wondering if anyone has tried the aftermarket heaters & if they work well

mark

004SL8991

The early Lexus seat heaters weren't very durable. When they failed on my 96, I phoned the stealership for a price on the elements, I was told I must buy the cushins to get the elements (big bucks). The ES elements were available seperatly, although slightly different (but do fit). Still quite expensive. As the butt and back heaters are series wired, if the one element breaks (either butt or back), nothing works. In my case it was the back element that failed. As the thermostat is incorporated in the butt element, I cut and connected the three wires that go to the back element together and restored the butt heater. Still functioning when I sold the car 2 years later.

toledo ron

Were the element wires for the heaters hard to get to? Can this be done with out removing the leather?

004SL8991

It's been a few years, but I recall the back element wiring is accessible by removing the seat back without removing the seat. Look for the 3 wire connector, join the wires together and try it. If the butt gets warm, you're in. Less than 20 mins work. Check a wiring diagram to make sure you have the right connector.

toledo ron

I took the seat backs off and used a meter to check for voltage and resistence. It looks like my passenger side butt heater is bad but the back is o.k. The drivers butt heater looks o.k. and the back has what looks like one of two circuits out; so I can try to salvage the drivers butt heater. One question though, do you know how the back heater wires to the three wire going to it. It appears to be two circuits but I can't account for how the three wires are used to work the two elements which are in series with the butt element. The black wire ties to ground, but I can't account for both the green and gray wires. Any ideas?

mkaye

there are 2 coils on the heaters, just wired in parallel

i just pulled the drivers seat out & replaced the back heater (seat was OK)
i put the seat back in, but the motors no longer work, i hear a click, but no movement
lumbar appears to work, but not forward/backtilt
did i screw something up, or there a reset sequence for the memory seats?

mark