Herbie

The water pipe for the rear screen wash goes up that pillar and I think there's a joint somewhere around there. It's possible that the water in the pipe has frozen, expanded, and forced the pipe joint to come apart.

Stick your head underneath and look up. You'll see two or three screws holding the bottom cover in place, so remove them and take off the cover for access to the switch panel.

This comes up often and never fails to make me incandescant because dealers really should know better If you take a multimeter and put the positive probe on the "special" jump start post in the engine bay fuse box and put the negative probe to any unpainted nut, screw, bolt, or bodywork, it will show 12V. There is no hidden or 'special' 12V source in that fuse box, or in the engine bay, or anywhere else for that matter. The 12V you're measuring is coming from one source and one source only, and that is the 12V battery at the back of the car, in the boot. That battery and that 'special' jump start post in the engine bay fuse box are directly connected to each other by a big cable. Ergo, 12V at the front is exactly the same as 12V at the back and it makes not one iota of difference whatsoever, which you choose to connect your jump leads to. The one and only reason not to connect directly to the battery is that the battery can generate hydrogen gas and there is a very small risk of ignition and an explosion if the jump leads spark when being disconnected. After more than 45 years of driving and 'hobby mechanic-ing' and after asking family, friends, workmates and others, not a single person has had personal experience of this, nor have they ever heard of it happening to anyone else, so it would appear to be more of a theoretical risk than a practical one. In conclusion, both the battery at the back and the jump post at the front are absolutely identical and equally viable places to connect jump leads/battery pack to from an electrical point of view.

PM just sent to you Dave.

Did you just look at it or did you actually check continuity across it with a multimeter? Sometimes they can look alright but fail to conduct.

1. In my 2018 RX there's a push switch up in the overhead panel that turns off the internal alarm sensors (shown below) and I'm sure your CT should have the equivalent somewhere. 2. DON'T pull any fuses and/or relays because if you do, you will wake something up and that's the last thing you want as it will lead to misleading results. I realise that you're aware of this but I see no harm in reiterating it for others in the future

This really IS the best way to check for a parasitic drain, including the procedure to put the car to sleep:

So it's a mechanical issue and you've ignored it for a year, so it's now got worse. Only two things as far as I can see - dismantle and fix existing ignition switch or buy a new one.

Time for that multimeter to earn its keep then. Good luck.

If the battery voltage is dropping quickly then it sounds like you have a parasitic drain somewhere, so these may help:

I'm sure there is but can't remember where. It sounds like you don't have an owners manual for the car so it may be best to go to: https://www.lexus.co.uk/owners/about-my-lexus/manuals and download one.

Can't be done as far as I know.

PM sent to you Stephen.

May be a silly question but I think the lights are only indicators - what does the actual transmission do?

Never heard of that - what is it?

Again, John's beaten me to the answer but yes, I agree with everything he's said.

I know that the struts do most of the heavy lifting and they keep it up there once it's open. They also make sure it's a controlled descent rather than just whacking you upside the head. Given that, I'd say that no, the motor alone won't open the tailgate but I'm not 100% sure, but the main problem is that the tailgate wouldn't rise equally on both sides if one strut was taken out.

No offence meant but that's bad advice. The tailgates are very heavy and if you take one strut away you risk bending something out of true.

It's 12V, along with almost every modern car. I seem to remember that motorbikes use 6V, but I've never known any car use 6V.

Presumably your owners manual will tell you. If you didn't get a paper manual, you can download a PDF one here https://www.lexus.co.uk/owners/about-my-lexus/manuals

No it's not, it was an excellent opportunity to enjoy driving a marvel of modern engineering.

PM sent Martin.

I'd agree with John - check and clean up all the earths (grounds) for both light clusters. This is classic behaviour for a corroded or broken earth connection. The factory where I served my apprenticeship had its own garage to look after the fleet of trucks and cars and I was in there one day fitting a couple of new mains sockets. While I was in there one of the skip trucks came in with the weirdest electrical fault I've ever seen. Whenever the driver pressed the brake pedal the windscreen wipers came on, even though the wiper switch itself was off. That turned out to be a faulty earth somewhere because the wipers were getting a backfeed from the brake lights.

You really don't want to be chucking money at it by replacing parts and hope that it works. Given that a ballast is so expensive you need to check and diagnose if that is indeed the problem and that a new one will fix it. Have you checked that it's not the bulb itself? Whichever is the faulty one, left or right, swap it over to the other side and see if the fault moves with it. If the bulbs are both working then do the same with the ballasts but be careful. It takes about 20-25,000V to strike the arc and about 80-85V to maintain it, so turn them off and leave for 10 minutes to let any residual voltage drain off before touching anything.

@tedd does that battery monitor just work as a basic voltage meter or does it work as a load tester and stress the battery? I was just idly thinking that if it's the former and it only shows the standing voltage, then it's thirty quid for a single-trick pony that does nothing else. Of course, it may well be brilliant at that one thing that it does and that's fair enough, but if anyone's interested, there may be an alternative to that. For just an extra fiver (admittedly plus £60/year for the SIM) the Rewire DB2 Tracker shows battery voltage along with a whole host of other things, as well as tracking the car and monitoring other parameters. This screendump is from my desktop PC but there are Android and Apple apps for use on phones and tablets.