1996 LS400 Front foglights and seat heaters not working

Howplum · April 16, 2020

Although they are not an MoT item, I would like to get the front foglights working. The bulbs look fine and the fuse also, which is getting power. Presumably there is a relay somewhere, but where? Once found, what is the best way to test it?

I appreciate non-working front seat heaters are common, but I thought I would investigate the simple options, just in case. Again, I assume there is a fuse and relay, but where.

Heater seems to be mentioned more than once in the fuse blocks, and there is a 30A fuse labelled SEAT FR.

Can anyone give me some guidance please?

Fuse block underneath the dashboard:

Fuse block in the engine compartment:

steve2006 · April 16, 2020

Not sure if the same applies but on mine unless the rear fogs are on the fronts will not come on, so try switching the rear fog lights on then see if the fronts then light up also. Seat heaters will 99.9% be the elements open circuit.

Howplum · April 17, 2020

According to the Owner's Manual "The front fog lights come on only when the tail lights are turned on", which seems an odd way of expressing it.

Anyway, having done a bit more research, it looks as though the relay is behind the footwell fusebox, so a little dismantling is required.

cruisermark · April 17, 2020

Howard I had my 1996 ls400 11 years ago - If you referring to the foglights which are built into the headlight IIRC they are turned on by turning the ring on the headlight stalk - I remember someone on this forum mentioning that when on they do not dazzle oncoming drivers and can be left on all the time and are very useful especially during night driving - I wonder if one of the Mark 3 owners can confirm this?

ambermarine · April 17, 2020

I have a story to add here that may throw some light on the subject .When my aerial failed on my Mark 1 I took the assembly out along with a relay that was fastened to the aerial frame assuming this had something to do with the aerial motors .

I fitted a aftermarket aerial and forgot about the incident, two years later the MOT guy was trying to figure out why the rear fog lights did'nt work .

After a few minutes he gave up and I had a fail we got out the Lexus wiring manual which I had for that car and traced the fault to a missing relay,I then located the old aerial and took off the relay plugged it in to the wiring and the lights came on. Two results came out of this incident the MOT station in question missed those lights not working twice and I learned never assume anything with Lexus engineering.

cruisermark · April 17, 2020

Hi

If you watch this video from 40:59 onwards - you will see him switch the foglights on - and then we he goes around to the front you will see them on

Howplum · April 17, 2020

Thank you all. I will investigate further - once I find the relay!

Howplum · April 18, 2020

The answer to the fog light riddle is quite simple. Not mentioned in the Owner's Manual is the fact that they only work with the engine running! Luckily I had the idea before I started dismantling the fuse box.

On 4/16/2020 at 9:29 PM, steve2006 said:

elements open circuit

In layman's terms, does that mean there is a break (or maybe several breaks) in the wiring?

Are the elements repairable or replaceable?

Can the elements from the rear seats be adapted to fit the fronts?

steve2006 · April 18, 2020

The seat element is similar to the filament in a light bulb, you apply voltage across it and it gets warm or in the case of a lightbulb it gets warm and produces light.

If the filament in the lightbulb breaks the circuit is broken and the light goes out, same applies to the seat heater elements, the voltage is present but no current is flowing so no heat.

Howplum · April 19, 2020

Thanks @steve2006.

Out of curiosity, has anyone tried, or considered trying, this sort of kit?:

https://www.amazon.co.uk/Heated-Warmer-heater-retrofit-Universal/dp/B0051BMMJ0

Obviously there is a lot of work involved in removing the seat covers, and connecting them to the original switch would be ideal, but they seem to get good reviews.

Malc · April 19, 2020

In our usual climate I've never really worried in the slightest to have my heated seats working ......... my bum soon warms up, even on a really cold day :wink3:

Malc

runsgrateasanut · April 19, 2020

2 hours ago, Malc said:

In our usual climate I've never really worried in the slightest to have my heated seats working ......... my bum soon warms up, even on a really cold day

Malc

So you can't be arsed! as the expression goes!

runsgrateasanut · April 19, 2020

Might give that kit a try, one day. Not happy my Seat has collapsed even after only 140k miles. Would prefer if it looked more like a Rover 75 seat at this stage in its life. Not made for the heavier person, just the lighter Japanese,😀 presumably.(Excluding Sumo Wrestlers!) 😀

runsgrateasanut · April 19, 2020

The thing with the Fogs on the Mk1 and 2 being lower down, in more childish moments you can put them on with S&T's and feel like Nightrider. Had them on my Toyota Mk 3 Supra which certainly looked more like the Hoffs Car !

As for actual benefit, I've found on back roads in France that the Fogs do absolutely nothing to help see ahead. If anything they make matters worse!

Aside

(still getting every correctly spelt word appearing with a red zig zag underline - think it may have something to do with Google - but what?) Fortunately it disappears when clicked on "Enter"

runsgrateasanut · April 19, 2020

Aside - sorted.

Right clicked after typing above two words and unticked "check spelling". Hopefully won't arise each time I make a contribution. Did go into Word program to see if it could be corrected from there and changes made, but seemed not to work? Baffled.!