Headlights Staying On

trickydicky02 · March 6, 2009

I don't have the light problem but my fuel gauge as recently stopped working and the fuel light is flashing,gonna try removing the connectors which are in the drivers side fuse box and check to see if any are corroded.How do you remove the plastic to allow easier access to the fuses etc...?

Steviewevie · March 6, 2009

I don't have the light problem but my fuel gauge as recently stopped working and the fuel light is flashing,gonna try removing the connectors which are in the drivers side fuse box and check to see if any are corroded.How do you remove the plastic to allow easier access to the fuses etc...?

Unclip the front part of the plastic door surround trim (on the floor) - you don't need to remove it, just loosen it a bit. Undo a plastic nut thingy deep in the footwell against the engine bay bulkhead (you should be able to do it by hand), which holds the side panel in. Then it basically just unclips and pulls out.

MacRS200 · April 4, 2009

Latest on my saga.

Stripped the dash on the drivers side and removed every box and connector I could see and checked the connectors all looked OK and it was dry. Took out the speedo cluster nada there. Removed the drivers side fuse box and checked everything including the relays and same as above. MOT 2 weeks away and the clock ticking, no horn no MOT!

Moved onto passenger side fuse box last weekend working around all the plastic trim inside car off the dash on the drivers side! Immediately found some corroded pins on the first connector that I pulled off, took the box out and found a few more. Cleaned them all up.

Took the passenger seat out to get easier access and worked on the plugs, cleaned them all up, blasted a hair drier around the connectors and general area on the fuse box and plugged up the box.

Bingo all working again, he typed touching wood Took the car in for MOT on Wednesday and it failed on a cracked screen on the drivers side.

Got a new one fitted yesterday, the fitter showed me the passenger side A pillar after he took the old screen out, you could see that the last screen had not bonded down the entire length! No wonder the bloody thing was leaking.

Anyway, fingers crossed ................................... :shutit:

aaronabbott · April 4, 2009

so it was all down to the passenger fuse box,any idea of what the corresponding connector was connected to exactly

Steviewevie · April 4, 2009

Sounds like good news Mac, fingers crossed that this is the end of it now, and that your story gives some hope to others with dodgy electrics !

aaronabbott · April 6, 2009

update on mine

received my new theft deterrant unit today that i bought off a breaker on eBay and fitted it and hey presto (touch wood) everything works as normal

redz_UK · April 6, 2009

well done mate!! finally sorted i hope!

u can get on with the mods now!

aaronabbott · April 6, 2009

well done mate!! finally sorted i hope!
u can get on with the mods now!

and clean that engine bay up

Steviewevie · April 6, 2009

Great news if that's sorted it once and for all ! Was the theft deterrent ECU not something you'd already swapped though ? Was it someone else who had tried that ?

aaronabbott · April 6, 2009

yeah but the new theft deterrant unit that i got hold of had a slightly different part number but still worked so will just have to see how long it lasts,but im gonna get a new windscreen fitted this week to make sure no water can get in from anywhere just in case

Steviewevie · April 6, 2009

Ah ok, my memory is working better than I suspected then , I thought you'd tried swapping it before. So did it work for a while but then the problem came back ? Which would sound like it was still leaking, as you say. Hope you really do get it finally sorted soon. Also hope my windscreen never needs replacing !

loggyboy · April 21, 2009

Ive just got back from Autoglass bracknell, they wanted to check it again, however when i got there he just looked at the screen and said that was all he need to check. He had made some calls and found that the Pilkington branded screens have a possible fault with the heated element cables causing sealing issues. So theyve agreed to fit a genuine Lexus screen, just awaiting a call back when they have sourced the glass.
Im sure ive read somewhere here about problems with pilkington glass??

Well the new genuine screen has been in quite a few weeks and we've had quite a few showers and all seems well. Just waiting for some persistant hard rain to really test it!

kev dood · April 21, 2009

interesting as I have a Pilkington screen from Autoglass on mine - and it leaked.

Though seems ok now though - tough wood.

Anyone have any links to the issues with pilkington screens then?

loggyboy · June 26, 2009

Ive just got back from Autoglass bracknell, they wanted to check it again, however when i got there he just looked at the screen and said that was all he need to check. He had made some calls and found that the Pilkington branded screens have a possible fault with the heated element cables causing sealing issues. So theyve agreed to fit a genuine Lexus screen, just awaiting a call back when they have sourced the glass.
Im sure ive read somewhere here about problems with pilkington glass??

Well the new genuine screen has been in quite a few weeks and we've had quite a few showers and all seems well. Just waiting for some persistant hard rain to really test it!

Still all ok now so it seems it was the glass that was at faut.

inflames · November 15, 2009

Hi guys i know this is an old thread but iam now having this problem with is200.

I spent most of my day looking at this yesterday with the help with my old man and were both electrical engineers. The windsrceen is the orginal lexus srceen but the sealant in the bottom had completely gone, so we put some sealant in to reduce the water getting in. Have you guys sealed up the grommet were the cables are coming into the foot well? I was thinking of doing to reduce the water coming in even more.

Iv got to go back to there today as its dryish so i can take the kick panel off and check the fuse box and clean all the contacts up and dry it even more as we had more rain here lastnight. My dad surguested we put another relay in the circuit going across from the ignition to the headlights, by doing this the head lights can only come on when the key is turned to on. Has anyone tryed this?

Pinewood · November 17, 2009

So has anyone found a definite problem for the lights staying on?

kam05 · November 17, 2009

Could be a faulty headlight relay- this happened to me a few years ago. Headlights stayed (wouldn't go off). Replaced the headlight relay and problem fixed. At that time, my car didn't have its windscreen replaced.

Pinewood · November 17, 2009

Yeah i was planning on changing the relay but Lexus want stupid money for it.

Has anyone got a spare one that i could purchase?

kam05 · November 18, 2009

Yeah i was planning on changing the relay but Lexus want stupid money for it.
Has anyone got a spare one that i could purchase?

Try a local motor factors- they should be able to supply a relay cheaper than Lexus.

Pinewood · November 24, 2009

This car is getting stranger by the minute. I have changed the relay and still the same. I am going to take it to a Lexus dealer but has anyone in the south east used a lexus dealer that has found the cue to this?

inflames · December 1, 2009

2 weeks now from when i sealed off the widow screen, gromet and cleaned all the contacts in the fuse/junction box. Its been Working fine had plenty of rain in this period aswell relay didnt click away or the headlights come on and stay on. Today went to the car to hear that dreded sound "click click" the bloody relay was at it once again . We had a bit of rain last night and the outside temp did drop a fair bit. This issue is realy starting to annoy me, guess its back to removing the headlight fuses when iam parked any were for a period of time <_< .

Was talking to my boss today about it and he surguested that i put some of those silcon gel packs in the area, to absorb the water and moisture. Am going to cover the cables in WD40 or some kind of grease. Has anyone else had any luck with this lately?

aaronabbott · December 1, 2009

cant you try and source a theft deterrant unit from a breakers as thats the part that controls the lights(i got mine for £20),i changed mine and its been fine ever since

new666uk · January 3, 2010

Hi all,

From what I'm seeing there is no definitive solution here - the problem seems to be too non-specific.

I noticed last night that the headlights had come on whilst the keys were safely in the house with me.

Tried so far:

Removing the headlight relay from the box by the Battery - works but annoying to have to pop the bonnet at the start and end of every journey.

Checked the fuses in the drivers footwell. Removed the cover and surrounding panel and checked for evidence of moisture. None around visible or felt.

Checked under carpet in drivers footwell. No moisture / damp.

Blew the footwell panel with a warm (not hot) hair drier to remove any missed damp.

Visually checked window seal at scuttle plate. Can't be sure of the quality of the seal and yes its a replacement window (second actually, the first one whistled and was replaced but that was before the summer. Might be worth arguing with Autoglass but unless I can demonstrate there is a fault with the seal they are unlikely to foot the bill.

What confuses me is that there is no sign of moisture (past or present) in the drivers well area. Is this a red herring?

Any other ideas welcome.

thanks

new666uk

Car details: 2001 Y reg is200 SE in Aztec Fire. Currently for sale...

eigenvalue · January 4, 2010

Well, I seem to suddenly have the 'headlights on' problem, together with many of the other symptoms described in this thread. Vehicle is a 2002 IS200SE. At the moment I cant re-connect the Battery (after charging) without the alarm going off - and the alarm can't be cancelled with the remote 'doors-open' button. Is there a way of temporarily disabling the alarm until things are sorted out? I appreciate that this may be intentionally awkward but there must be a way? I have removed the headlamp and horn relays in the meantime. Where is the 'self-powered' siren located and what kind of Battery is used? The User Manual says that it requires 'maintenance' - anyone know what needs to be done? I am just about to inspect the junction board in the driver's footwell.

I removed the drivers door switch for inspection. It is on a very short wire - can it be disconnected and opened for contact cleaning?

Would be very grateful for any advice......

eigenvalue · January 5, 2010

.......a quick update on the above. The door switches are all working fine. The Relay Board in the driver's footwell is perfectly dry and everything looks 'like new'. Moved all the connectors and wiring, pushed relays and fuses, etc. but the problems still remain. It has been exceptionally cold here which may, or may not, be coincidental. The engine itself runs OK.

I can't help feeling that there must be a common factor to the symptoms - headlamps switching-on by themselves, petrol gauge reading below zero and flashing, outside temperature gauge reading 'E', MPG meter not working, engine temperature gauge not working, alarm going off, security light continuously flashing..... Could the problems relate to the Anti-theft Alarm ECU unit? Can anyone say if this unit can be opened or is sealed - I am an electronic engineer and well know that many problems are simply failed solder joints, capacitors, or high value resistors. It is a different matter however if it is a failed programmable device or trouble within a multi-layer circuit board.

I intend to look at as many of the other connectors as I can find, e.g. to the Combination Meter unit (instrument dials unit), and also at the board in the passenger's footwell. Beyond that I am getting a little stuck.

If anyone can offer any suggestions, I'd be grateful.