Headlights Staying On

[Steviewevie]

ok, don't know what year your car is, but here is the wiring diagram for the automatic light control for models up to mid-2001.

Have a look towards the bottom middle of the diagram. You'll see connector IH3 mentioned there, with connections between the Theft Deterrent ECU and the Theft Warning Siren.

[aaronabbott]

ok I am pretty sure that connector is called IH3. Still trying to find exactly what goes into it.

Edit - see this diagram

lookin now,

thats near as impossible for me to understand

[Steviewevie]

thats near as impossible for me to understand

Which one ? Did you see the last diagram that I posted, the one with the wiring for the automatic light control ?

It is showing that there are three wires relevant for the automatic light control that go into that grey connector (IH3). There is a blue wire with yellow stripe(L-Y), a blue wire with an orange stripe (L-O) and a white wire with a red stripe (W-R). That IH3 connector is between the theft deterrent ECU and the theft siren.

When you say that you think the problem is there, is this just a red herring though, e.g. by wiggling the wires you are making one of them come loose and turn off the lights ? Not sure if this is a good indication that this is the actual cause of the fault rather than just a side effect.

[ruairibray]

blimey!!!!!

just been reading my old posts on this headlight staying on after car is off issue.

first time ive read this topic in like 2 and a half years .

wish i knew back then what i've read in this topic about this problem....coz it would have saved me £600 pounds at lex manchester!!!!! RIP OFF B*****DS!!!

Mate -How did you get your fixed/sorted? I've had the fuseboard checked/the alartm ecu replaced and still its happenin. Lexus won't tell me anything other than that they will need a couple of hours to investigate but if I go to them and tell them the probelm I reckon I can save some money.

Would appreciate any info you may have!

[aaronabbott]

thats near as impossible for me to understand

Which one ? Did you see the last diagram that I posted, the one with the wiring for the automatic light control ?

It is showing that there are three wires relevant for the automatic light control that go into that grey connector (IH3). There is a blue wire with yellow stripe(L-Y), a blue wire with an orange stripe (L-O) and a white wire with a red stripe (W-R). That IH3 connector is between the theft deterrent ECU and the theft siren.

When you say that you think the problem is there, is this just a red herring though, e.g. by wiggling the wires you are making one of them come loose and turn off the lights ? Not sure if this is a good indication that this is the actual cause of the fault rather than just a side effect.

cheers steve i just cant understand the electrical diagrames,

im off work from wednesday so ill get back looking into it,btw where does it say the wire colours?

[Steviewevie]

im off work from wednesday so ill get back looking into it,btw where does it say the wire colours?

Codes for the wire colours (e.g. L-Y) are given on the diagram. The meaning of these codes are here (scroll down to the same page). That document will also tell you lots more about how to read the wiring diagrams.

[aaronabbott]

im off work from wednesday so ill get back looking into it,btw where does it say the wire colours?

Codes for the wire colours (e.g. L-Y) are given on the diagram. The meaning of these codes are here (scroll down to the same page). That document will also tell you lots more about how to read the wiring diagrams.

cheers steve plenty of reading for me to do while im at work then :winky:

[k33rjd]

PLEASE READ

Before you start taking relays out and paying large bills

if you have auto lights and they are staying on when you have left the car (and locked it) then the first thing to check is the door switch for the drivers door. this can be done by unlocking ur car and opening the door- does the interior light turn on?? if not then this can be the fault. damage, wear and corroision can make these fail, this sends the signal to the body ecu which turns the lights off when car is locked. if this is ok, then check your windsceen for the made in japan sticker in the top right hand side, if its not there then u have had a screen put in, next check for water entering the car around the seals with a pressure washer, this is done by pulling the footwell cover off and checking for dampness, if this is so then this is where the lights are common to fail.

[aaronabbott]

PLEASE READ

Before you start taking relays out and paying large bills

if you have auto lights and they are staying on when you have left the car (and locked it) then the first thing to check is the door switch for the drivers door. this can be done by unlocking ur car and opening the door- does the interior light turn on?? if not then this can be the fault. damage, wear and corroision can make these fail, this sends the signal to the body ecu which turns the lights off when car is locked. if this is ok, then check your windsceen for the made in japan sticker in the top right hand side, if its not there then u have had a screen put in, next check for water entering the car around the seals with a pressure washer, this is done by pulling the footwell cover off and checking for dampness, if this is so then this is where the lights are common to fail.

none of these points apply to my problem,

windscreen is original,

no dampness anywhere

all door switches work 100%,

something somewhere is holding a negative feed on that circuit which is reversing the way my lights are working

[k33rjd]

the door switches on the body, on the bpost?

how did you check them?

its the switches on the body which tell the ecu when a door is open that you need to check. turn your interior light on so its on 'door', and open and close each one in turn making sure the light illuminates when opened. if you find that one opens and the light doesn't illuminate (normally the drivers) check the 10mm bolt hold the spring door switch onto the body. this is the earth point signal for the lights etc.

the auto lights should come on when the ign is on and at a set darkness. then as you turn the vehicle off and open the door it turns them off, as the signal that you have left the car is sent to the ecu. hope this helps, if not then please pm me and i can help further.

[aaronabbott]

the door switches on the body, on the bpost?

how did you check them?

it makes no difference if the doors or closed or open for the lights to be on or off when the ignition is off

[k33rjd]

it does make a difference wether the doors are open or closed. they dont turn off till the door is opened.

this is so the lights stay on till you get out of the car, if it doesnt recieve the signal that the door has been opened then they will stay on as it thinks you are still in the car.

[aaronabbott]

it does make a difference wether the doors are open or closed. they dont turn off till the door is opened.

right from the start,

my lights come on with the key out of the ignition (ignition off position) the door can be open or closed the problem still occurs,its like the circuit is reversed

[k33rjd]

take it you have auto lights?

[aaronabbott]

take it you have auto lights?

yeah,all the rest of the lights work (side,tail,fogs) just not the headlights.they only come on when the ign is off and cant be switched on either when ign is on

[k33rjd]

i c, do appologise, most of the probs on this thread are for the lights staying on when car locked. thought urs was the same. no yours deffo wont matter about the doors like u said.

[k33rjd]

what year is ur car?

[aaronabbott]

what year is ur car?

2000 w

[k33rjd]

and does ur flash (headlight) work when ign is on?

[aaronabbott]

and does ur flash (headlight) work when ign is on?

no,only work when ign is off,thats when i found the plug and gave it a wiggle and the lights went off but came back on again shortly after

[k33rjd]

a silly question but have you checked all of your fuses?

especially the- 120a alt, 7.5a ecu-b2, 10a ecu-ig fuses

[k33rjd]

the only thing thats really sticking out is the theft deterent ecu, this is controlled by the ign and in turns controls the lights.

[Steviewevie]

no,only work when ign is off,thats when i found the plug and gave it a wiggle and the lights went off but came back on again shortly after

That's why I think wiggling that connector *might* be a red herring, i.e. it is part of the circuit but perhaps it's nothing to do with the problem, i.e. it's just another way to turn the lights off. Not sure though.

[k33rjd]

which connector is it ur wiggling? ih3?

[aido]

Just thinking is it worth giving contact cleaner a go or compressed air on the connectors in case they got damp in the past and it's oxidisation or something stupid?