Low beams don't work at all but high beams do.no pwer to the fuse
 

No power at the fuse.changed bulbs.the old bulbs we're good. There was an old thread that the number 2 relay box was a common occurrence for failed lowbeams but in researching that statement the number 2 really box only houses heater relays. Three of them. Could it be these guys were talking about the number two fuse box that houses the two 15 amp fuses on the passenger side engine compartment. I googled headlight relay for my 07 460 and it shows or at least brings up a relay but for the life of me I can't find where it goes or if the search result was true.i don't have the rescources to continually spend on trouble shooting this. I'm wondering if I can just replace the whole headlight assemblies with after market LED and could that bypass having to replace mysterious fuse/relay box and labor fees

Yes the do. My running light work just no low beams at all. Someone from an old Post had mentioned that it's becoming quite common the situation I'm in. I haven't checked the ballast on either side of the car. I don't know how. I could probably test to see if there is power to them but I'm still investigating on how to drop the bumper cover..

I don't think replacing the housings with LED is going to help you given you don't have power to the unit. While a ballast is a likely culpret when talking inop HIDs, it isn't likely both would be bad at the same time. You've already gotten most of the way through the troubleshooting, you don't have power at the fuse, therefore obviously that is your problem. You need to trace the power diagram back and figure out the routing. Any aftermarket equipment installed? Dash cams, remote start, alarm, sound?
On a side note, even if a fuse shows to be good you might change it anyway-I only say this because I've had this strange phenomenon occur.

Nothing after market. Im looking to trace the fuse back or where would I start the trace. Is there any way to access some power to just see if the lights work before dropping the bumper cover to access the light. I'm really not in the position right now to buy ballasts that I don't need if I could test them somehow..RT now I'm squeaking by with the high beams because of work. And to drop the bumper where it would be parked and usage not good. I may have to invest in an entire weekend for this but I'm still open for input. I looked back into the archives again and it seemed someone had the same issues and replaced the relay or fuse box? I'm also told that it's or could be an integrated relay in such fuse box? Also the it's a type of four point system to even operate the headlights. My cig lighter dosent work but I really don't believe that it has any contribution to the problem at hand.

Don't over complicate your problem. This is autoshop 101- go back to basics and figure out why you don't have power to the fuse box. If you can locate a wiring diagram this will help you trace the power routing for the headlights, then it's as simple as tracing it back to the relays, testing them, etc.... You could have a wire short somewhere, a component that is shorting, a bad relay, a bad switch, etc.....

When you say no power to the fuse panel--you're pulling the fuse and testing the inbound power at the box for voltage? With the switch on you have no power there?

You can use any 12 volt battery to apply power to components with wire extensions. I have a small mower battery in my shop connected to leads for this type of troubleshooting. You might start by applying power to the outbound fuse panel side to see if the lights come on.

I had that thought enter my mind but couldn't quite get my head around it but now you say it it makes sense. I love this forum the people here have helped me so much. And thank you for the starting point. Gonna try tommorow will keep you posted!!

Hey did you get this fixed as I'm having the same issues on my 08 ISF.
Is getting annoying now

No haven't gotten it fixed. Lexus was trying to piece meal it .first changing the relays and the fuses and the bulbs then wanting to change the ballasts and then finally the fuse block. I have researched this and 90% of the time it's the #2 fuse block. I don't have the 1000 bucks they want to fix it but I think I may have to bite the bullet and just do it. I'm getting by on just using the high beams but it's quite aggrivating like you said. Im now researching some auto electric places but I'm afraid that I don't know enough about that to be effective. If you have any luck please let me know. This actually is a very common problem,I don't understand why there isn't more info about it!!!

Thanks for the feedback, That's my thought as well, not much info is on this.
I came across the relay block 2 as well in my search.
I'm going to do a few more checks this week but it's really Frustrating!!
I'll keep you in the loop if I get any headway.

Thanks alot for confirmation. Ttys

I am the other guy, #2, where this thread started. The original one with the issue had the dealer replacement after making the mistake it was a cheap relay. It turns out you need to replace the whole block since it is integrated. Im tired of pm-ing so here it goes so others can find this in search:

The chances of you having this issue on a 2007/2008 car are 100%. It is only a matter if when, just like the brake controller failure. Symptoms start just like the HID bulb failure where one side or both start but go off intermittently, but sometimes turn and stay on with a few cycles of the headlight switch. Eventually one side will stay off, and you will notice no power to the corresponding fuse. THIS IS YOUR MAIN INDICATOR - DO NOT WASTE YOUR TIME WITH THE BALLASTS UNLESS YOU HAVE A WATER BREACH OR OTHER HIDDEN ISSUES WITH THE HEADLAMP ASSEMBLY. (I will get into testing ballasts later). If you have ANY other issue, like a popped fuse, it is something else and not the junction box. I have attached a picture for reference. I and many others on and not on the forums have tried to remedy this issue another way with no avail. If you can dismantle the box, test, prove, and show a different fix, more power to you, but many of us do not have the time. The switch rarely fails (different symptoms), ballasts rarely fail, wiring rarely fails unless there are hidden issues (rodents, accidents, previous owners).

https://cimg3.ibsrv.net/gimg/www.clu...5f24fc058.jpeg
Now, if you were getting power at the fuse, there are two ways to test the ballasts, both include the messy fun of front end disassembly:

1. Remove wheel well covers > remove lower splash guard > remove front bumper > unplug HID bulb connector > disassemble ballast cover under headlamp assembly > unscrew ballast from headlamp housing > repeat on other side > reassemble one unit with opposite ballast to test.

Are we having fun yet?

2. Remove wheel well covers > remove all front and side engine covers> remive lower splash guard > remove front bumper > unplug HID ballast connector > Unbolt Headlamp assembly > pull out headlamp slowly and disconnect washer hose > repeat on other side > plug in opposite headlamp to test.

3. I don't care what that other guy says in one thread, but DO NOT JUMP THE FUSES BETWEEN THE LOW BEAMS unless you want to have a smokin’ hot bod because you just set your car on fire.

Like I said, unless there are hidden issues ballasts will not be your problem. This has become a common issue and Lexus techs are well aware of the procedure now. Good luck.

Thank you. I was pretty sure of what you were saying. I was going to go to the dealership and force them to change the block. Initially I went and asked them to do the procedure but it was like they didn't want to hear it.!!! Absolutely rediculous. I'm just wondering what an approximate price would be. Anyone care to chine in on that please!

Relay block#2
Understood sir and thanks.

I'll let you Know
Edit: when you say, replace relay block, do you mean all of the relays in engine room r/b No 2??

It comes as an entire unit and is priced as such. This was a HUGE PITA when I was going through this ordeal since no one was available to help. The only other thing is to stay firm with the dealer to not have them waste your time with bad diagnostics and replacements to get to this step if you meet the conditions above. When this fixes your issue, please post and say it did so this issue can have have a definitive thread and solution, not buried in search results.