06 Rx400H High Beams Suddenly Quit

[volosong]

On a recent road trip to visit a friend in Montana, we arrived at her house late one night. All lighs on my 2006 RX400H were working fine. The next day, the high beams would not work, and have not since. All other lights work as they should. When the high beams are switched on, the blue indicator light on the dash illuminates as it should, but the actual high beam lights do not come on. Fuses are good.

Any ideas?

[RX400h]

I'm not sure if this is the case with our cars, but some Toyotas' dimmer switch provides ground for the high beams. If so, a bad dimmer switch may be the problem. Other possibilities are the relay and column swtch, itself.

[volosong]

Is it possible that if one bulb burns out, that the good one will not illuminate when switched on?

[1990LS400]

It seemed bizarre when it happened but I've had halogen headlight bulbs fail within a day or two of each other. Have you owned your RX since new and know that aftermarket shorter life (e.g. Silverstar) high beam bulbs have not been installed? I would first replace both high beam bulbs - a two-pack should cost maybe $20 at a discount store. If they still don't light up, the problem cause could be many things including corrosion on a fuse block. An automotive electrician should be able to quickly identify the problem if it's not the bulbs.

[cduluk]

Is it possible that if one bulb burns out, that the good one will not illuminate when switched on?

Do the high beam bulbs illuminate as they normally should in DRL mode (during the day)?

If one bulb burns out, both will remain OFF in DRL mode. However, if one burns out, the remaining bulb should illuminate in high beam mode.

[volosong]

I will have to check exactly. From what I remember, they do not come on when dark or during the day ... but I can't be sure about during the day. I'm parked against the garage door right now and will go out and try them. Will report back later today.

[maseace]

Remember you have to take the parking brake off to turn on the DRLs with the system in ready mode.

[volosong]

Remember you have to take the parking brake off to turn on the DRLs with the system in ready mode.

Didn't know that. I assume I can leave it in "Park" transmission mode?

[maseace]

Remember you have to take the parking brake off to turn on the DRLs with the system in ready mode.

Didn't know that. I assume I can leave it in "Park" transmission mode?

Yes. The DRLs normally come on as soon as the parking brake is disengaged, in any gear.

[cduluk]

Just turn the ignition on during the day with the lights switch set to off or auto.

[volosong]

Sheech! I have a love/hate relationship with this car. On one hand, it is the "best" car I've ever owned. That is to its comfort, amenities, power to mpg ratio, versatility, etc. On the other hand, there are no Haynes or Chilton manuals available for the diy people. We are slaves to the dealership. I have had a difficult time finding an independent mechanic that I trust to service the vehicle. My Mercedes mechanic is wonderful and takes care of routine maintenance, such as filters and oil. But anything complicated, he begs off. (On a side note: anybody who can recommend an independent mechanic they use in the San Fernando Valley region of Los Angeles would have my eternal thanks.)

Anyway, after about an hour of web searching, with no results, for a picture identifying front lights, I gave up. I think, and I'm not sure, but the fog lights are in the bumper. That is easy. The low-beam lights are separate and come on either when the headlight switch is turned to the on position, or if set to auto, they come on when it gets close to dusk. I normally leave my lights on auto.

The high-beam lights are in a seperate housing and function as either daytime lights or high beams, depending on the switch. I think that the small bulb at the top of that housing is the parking light. I had thought that it was the DRL, but it appears that I was wrong. The DRL/high-beam is the same bulb; the amount of voltage determines its current state.

What I could not check is if the parking light goes out when the car is in motion. I could not check that by myself. I'll need another person. What I did is turn the key to ready, release the parking brake, leave the vehicle in park, and go outside to check the light configuration. The parking bulb was lit, but not the DRL. When I turned the low beams on, they were indeed on, the DRL was still out, and the parking bulb was still lit. When I turned the high beams on, the dash blue idiot light came on, the DRL/high beam light was still out, and the low beam lights stayed on.

Any ideas? This Friday, I'm going to ask my Mercedes mechanic if he would replace the DRL/high beam bulbs. I got a set of Sylvania Silverstar bulbs to insert.

Can someone verify that under normal conditions, the low beam goes out when the high beam is employed? Also, that the fog lights extinguish when the high beams are turned on? Thank you all for helping.

I'm not going to be very happy if it is an expensive repair. Even several hundred dollars. The car is about 20,000 out of warranty and I realize that some people might say that if one can not afford to maintain such a car, they shouldn't own one. Maybe I shouldn't. There is just something about paying almost $200 for a simple oil change when my Mercedes dealer does it for $55, filters included. And, he also checks all the fluids, pressures, and brake linings at the time.

[maseace]

The low beams (and the fog lights) go out when the high beams are on, by design. Motion has nothing to do with the lights, the DRLs will be on whenever the parking brake is off and the headlights are off. DRLs will also light if just the parking lights are turned on. You can check it by yourself. You are correct that the DRLs and high beams share the same bulb. So if one or both go out, you will not have DRLs or high beams.

You CAN get a service manual - I bought one on eBay a few years ago, on CD. It has full schematics, install/remove instructions with diagrams, and troubleshooting guides. Some operations involve a Lexus diagnostic tester computer, but many things can be worked on at home.

Link: http://www.ebay.com/itm/Lexus-RX400h-Repair-Manual-Wiring-Diagrams-Body-Manual-2004-2005-2006-2007-/261202929512?pt=Motors_Manuals_Literature&hash=item3cd0e86768&vxp=mtr

There is a fuse and a separate relay for the DRLs/high beams, so check all of these if the replacement bulbs don't work.

[volosong]

Thank you for the link to the manual. I'll check it out. In the interim, I went to my lady's house for a late supper and had her watch while I drove slowly toward her.

First time, (it's getting dark), parking brake off, transmission in drive, lights on auto. Result: the low beam was on, the small parking light bulb was on, and the side amber light.

Second time, parking brake off, transmission in drive, lights on auto, high beam switch on. Result: same as above, (low beam on, small parking light bulb on, side amber light on), and the blue dash indicator light was on.

So, I don't know what is wrong. I wish to ask, if one DRL/high beam light burns out, does the other one not illuminate when switched on? In other words, one bulb out, both lights no work.

Thanks again for all the help.

[maseace]

I can confirm that the high beams still work with one bulb disconnected (just one came on), so I suspect either both bulbs burned out, or you have a DRL or high beam relay or fuse that's gone bad. You can try swapping relays if you have another with the same part number (there are several identical relays in the fuse/relay boxes).

[maseace]

Here is some info I found on the service manual. Check all the relays, especially the DIM relay.

HL.pdf

[Paticake]

I have an 06 also, and recently lost both headlights at the same time. I was concerned it was more than the light bulbs because the left headlight was replaced in 2010 and the right was original, how could they burn out at the same time? Did the internet search and went to the local garage armed with all kinds of solutions.....

$30.00 and 15minutes later, all I needed was new bulbs. Good as new.

Good luck.

[volosong]

You CAN get a service manual - I bought one on eBay a few years ago, on CD. It has full schematics, install/remove instructions with diagrams, and troubleshooting guides. Some operations involve a Lexus diagnostic tester computer, but many things can be worked on at home.

Link: http://www.ebay.com/itm/Lexus-RX400h-Repair-Manual-Wiring-Diagrams-Body-Manual-2004-2005-2006-2007-/261202929512?pt=Motors_Manuals_Literature&hash=item3cd0e86768&vxp=mtr

Ordered.

Thank you all so much for your help. I've checked the fuses, but will do so again, this time with a multi-meter just to make sure they are good. Friday, I'm going in to see my Mercedes mechanic and have him replace the light bulbs. Hopefully, the service CD will arrive by then and I'll take that in also so that if the new bulbs don't solve the problem, he can check the relays.

I have another general question ... it is my understanding that under the skin, the RX400H is the same mechanics as the Toyota Highlander hybrid. For a specific part, will they have the same part number? And if so, have you found that the part is less expensive from a Toyota dealer than a Lexus dealer? Or the same price? (I have no Lexus dealers nearby, the closest being about 40 miles away, but do have a local Toyota dealer.)

Thanks again, everyone. I have a question about my auto dimming center rear-view mirror, but that can wait for another time.

[maseace]

Parts.com has OEM Lexus parts cheaper than Lexus or Toyota dealers. You can look things up by part number or diagrams. But it is true they share a lot of parts, so if you have the part number you can probably get it from a Toyota dealer for less. My nearest Toyota dealer happens to be ridiculously expensive though.

[1990LS400]

I don't do much heavy work on cars anymore but the last time I needed Toyota parts (Prius v wagon) the cheapest I found was at http://www.carsontoyota.com/parts/ in Carson CA.

I've gotten great service and prices on parts from http://lexus.sewellparts.com/ in Texas but they are due south of me and shipping charges are fairly low.

[cduluk]

Parts.com has always had the lowest price (even if you include shipping) for all OEM Lexus parts. I love the site!

[volosong]

UPDATE.

We don't seem to be able to edit tread titles. Anyway ...

I took the car into my Mercedes mechanic for a routine oil/filter change this morning and asked him to install the new light bulbs that I purchased while on the trip to Montana at the beginning of this month. I gave his helper the background info, that I checked the fuses, but wished him to double check. Told him about the relays and gave him the printouts that maseace linked to in reply #15 and also ordered/received the owner's manual that was linked to by maseace in reply #12. More on the manual in a moment.

The lights now work! And the "problem" was the old bulbs. I do not know if the mechanic checked the condition of both old bulbs, if one were still goood. Only after I left the shop did I think of it. Anyway, it appears that either both bulbs fail at the same time, or if one bulb burns out, the good one will not illuminate.

Thank you all so much for your help and encouragement. I "love" my car again.

On the manual ...

I was unable to get it working on my netbook computer in the shop. If you are considering ordering this digital manual, be forewarned that you MUST be using Microsoft Windows Internet Explorer. That is a problem for me because all my home computers run Linux Mint, and IE is not available for that operating system. For my browsing needs, I use Firefox, and even if I were to be running windows for some reason, (photoshop), I would still use Firefox.

More "testing" needs to be done, but I just might have to send the disc back and get a refund. I don't remember the eBay advert specifying that one needs to use IE to view the shop manual.

Thank you all again.

[maseace]

Yeah you have to use IE because the manual uses Adobe SVG viewer, which was only supported by IE, and the newer versions of IE still have problems reading the SVG files.

[RX400h]

The latest IE is actually very good. I run Win 8 Professional at work, which comes with IE 10. Page loads are lightning quick and safety features are abundant.

As an aside, my son tells me that a program called "Wine" can be used with Linux. Once Wine is installed, "Chrome" can be installed. Chrome has an IE mode, which may work to view programs that can be viewed only with IE.