Light Puzzle

[BobSport]

I had a wee problem yesterday that I hope someone can help me understand and hopefuly resolve. Moved my car from one parking space to another about 9.00 am went indoors for some breakfast and then was going to work about 11.00 and noticed that the engine was a bit sluggish turning over, thought oh no Battery is on way out, its been very cold over the last couple of weeks so not too much of a surprise. Went to work and parked up, about 2 hours later one of my colleagues phoned from the car park to say that my lights were on, went down to car and saw that both headlamps were lit but not the taillights. I usually leave the light switch on auto so I got in car and turned the switch to off, but the lights didn`t go off, started engine, turned lights back to auto and then off again, still no luck, switched on and off a couple of times , started engine and turned off and eventually got the lights to go off. Went back to work and about 2 hours later got another call saying the my lights were on again, went back did same things again and got the lights to go off again, about 2 hours later got another call saying lights were on again, this time engine wouldn`t turn over but lights were still on, had to pull the relay to get them to go off and then had to get jump start to get me home. I left the relay out overnight so that the Battery wouldn`t drain and went to see my local mechanic this morning. We got the lights to stay on when they should have been off but are unsure whether the fault is with the light switch or possibly the ignition switch, any ideas guys? I have put the light switch on off ast the moment and it seems to be Ok but am anxious about leaving it in case I get stranded.

[Paradroid]

When I went to pick my car up when I bought it the dealer said he'd had to charge the Battery because he found it was Battery flat that morning, and it was because the lights were on auto.

I thought nothing of it at first but later when I thought about it, I couldn't work out how it had happened. Since it was locked up inside his garage, I thought he might have left the keys in it and the ignition on or something, otherwise I couldn't see how the lights would be on.

Maybe there's something that can cause this. It's never affected me since because I don't use the auto lights.

I know it sounds daft but have you checked the manual, maybe there's something in there that might explain it.

[Steviewevie]

Have you had your windscreen replaced recently ? Water getting into the electrics for the auto sensor can seem to cause this sort of problem.

[loggyboy]

Its a commonish fault... lots of disccussions here http://www.lexusownersclub.co.uk/forum/ind...showtopic=28384

[BobSport]

Have you had your windscreen replaced recently ? Water getting into the electrics for the auto sensor can seem to cause this sort of problem.

Hi, Yes I had my windscreen replaced in June this year, I will have a look at the fusebox and see if its damp, Cheers everyone for your help.

[Parthiban]

Think you'll need a new headlight relay, and to give whoever replaced the screen a good kick up the a**

[BobSport]

Hi again, just had a look at the fuseboxes and there does not appear to ba any signs of damp anywhere and all seems well with the lights today. I will wait and see if there is a repeat performance and investigate further then. Thanks everyone again for all your help.

[Paradroid]

Hmm that's interesting. My car has the original Lexus windscreen and the lights on problem only happened once for the dealer it's never done it for me. I'll put it down to him doing something stupid then :)

[aaronabbott]

it doesnt event have to be damp,jus a bit of moisture will short the system out on the theft control unit (which controls the lights,just behind the ignition ring),trust me ive got the same problem,had it on and off for ages now.only thing that will fix it is either a new fuse board and theft control unit.

try and using a hair dryer on the fuse board and wiring if your lucky it might dry it out for a bit

[Steviewevie]

it doesnt event have to be damp,jus a bit of moisture will short the system out on the theft control unit (which controls the lights,just behind the ignition ring),trust me ive got the same problem,had it on and off for ages now.only thing that will fix it is either a new fuse board and theft control unit.

Please excuse my lack of understanding on this issue, but can't you get your windscreen re-sealed to stop it happening ?

[aaronabbott]

i surpose you can,but my screen is the original and never been replaced so somethings wrong somewhere along the line