"brake Light Out" Indicator On Dash

[Arkansawyer]

ADDED INFO: This only happens when the headlights are on. With the headlights off there is no warning light.

I know you guys are rolling your eyes when you saw the post.

Yes I have searched and read everything on this subject and have tried the majortiy of the "fixes".

Replaced every bulb today in high mount brake light, all tail lights, reverse lights, tag light and front marker lights. Cleaned every bulb contact point and used bulb grease at every location. To no avail.

The twist in my particular instance is that whenever I press on the brake pedal the warning light in the dash goes off. As soon as I get off the brake pedal the light comes back on.

I have not dug into the trunk hinge yet to see if I have the broken wire issue. It was my understanding that if this were the problem I would be experiencing more electrical maladies than just the above.

True or no?

[CUMan]

It seems that the possible things that will happen with the broken wire in the trunk hinge problem are infinite in number. In my case, the trunk would not open when the inside release was pulled; the transmission indicator lights in the dash would flash; and there was a weird feel to the brakes. Other folks have reported strange transmission shifting patterns.

So, yes, I would say it is possible that you have the broken wire problem.

[1990LS400]

Although my previous 90 LS had the "broken wire in the trunk hinge" problem, I had another problem that caused the warning light to alternate between being off and on.

My 90 LS was wired for towing a trailer and there was a loose connection where the installer tapped into the electrical loom in the trunk. Once I fixed the connection, the warning light never came on again.

When I had the broken wire in the trunk hinge, the related transmission shifting problems did not start until the wire had separated almost completely.

I do not know at what model year the trunk hinge wire issue was resolved.

[wwest]

For some reason the ECU that monitors the brake light filament "thinks" the brake pedal is always depressed, so it is continously checking for filament current flow. When the brakes are actually applied it "sees" current flow and that makes it "happy".

[dfkd]

That's how it checks if anything is blown though...by a weak charge running through the bulb itself. Must be some corrosion somewhere.

[Arkansawyer]

OK guys. I just got finished unraveling the black tape and checked the trunk hinge wiring. Everything looks perfect. Even took off the Black "warning light" box and looked at the circuit board and all looks fine. I even went back and replaced one of the bulbs that was a different brand so that they were all from the same manufacturer.

No change.

One other thing that I forgot to mention in my earlier post was that the warning light only comes on after I turn on the headlights. It does not come on at all during the day with the headlights off.

I remember that in some of the other posts some members mentioned ground wires that needed to be tightened to make good contact. Where might these be located?

Are the fog and headlights included in this "circuit" as well?

Thinking about just putting black tape on the dash to cover the light. But I'm anal and like everything to work as it should.

[SKperformance]

Get your alternator checked.

It may be workign properly but that slight variance in power can cause problems.

[Arkansawyer]

Will do.

I have been noticing the slightest of alternator "whine" lately.

It seems now to initially be off on startup with the headlights on. Then after 10 or 15 seconds it appears.

All in all I am loving this Lexus.

[Arkansawyer]

Car was idling really low last night and revved it slightly to notice that the warning light went off.

So tow things. I do believe my alternator is on its way out as metioned by SKperformance and secondly that this is causing this warning light to appear.

The previous owner said he had just replaced the battery. Which may be inconsequential but leads me to believe that the alternator has been dying over time.

AutoZone was the only place to have an alternator and I'm a little concerned about the quality. Especially after seeing the recent post about someones PS pump, that they bought at Autozone, failing.

Should I go Napa? Seems they are the only ones that might have one locally.

[wwest]

Replace the alternator's $3.00 slip ring brushes first, just in case.

[nc211]

Per wwest's post. I believe it is #6 in the attachment.

[Arkansawyer]

Are you guys talking about replacing the slip ring in the new alt. or the old one?

Where could I pick up a slip ring brush? We have several rebuild shops and a couple Toyota dealers locally.

[nc211]

It's such a cheap but important part that I wouldn't go with aftermarket or rebuilt, I'd buy a new oem one. I'm not 100% sure if that's the part # in the picture or not, just comes close to the description. Maybe wwest will post up again with the answer. That part is listed for $13 on www.lexuspartsonline.com.

[Arkansawyer]

UPDATE!!

Ordered an OEM alternator from ebay and got it yesterday. Took it to an O'Reilley's where the kid said it was bad. He was new and barely knew how to hook up the alt to his machine. So I took it to a local rebuilder and had him test it and he said it was fine. So I asked him if he wouldn't mind testing the one in my car. So we hooked it up and all appeared to be OK with my original alt. I asked if I could turn on the headlights and that's when things changed. After turning on the lights the alt is supposed to come up in output and instead dropped. Hence the reason my "rear tailout out" indicator comes on when I turn on the headlights.

So I am having the ebay alt. rebuilt even though it checks out OK. I don't want to go through the trouble of putting on an alternator that might last two years or only two days. I told him to pay particluar attention to the slip ring bushings as someone had mentioned in this thread. I will update again when the new/rebuilt alt. is put on.

Thanks SKperformance for the heads up on looking at the alt as the culprit.

[Arkansawyer]

Just got finished installing the rebuilt alt. and it did not fix the light issue. However the lights don't dim nor does the blower motor slow down when I hit the brakes.

But that damn "brake light out" lamp in the dash is still there!

Was sitting in the drive way resetting my memories with the engine off and the key still on I noticed that when I would telescope the steering wheel in or out the warning lamp would go off until I stopped telescoping.

Does this ring a bell with anyone? This is starting to get crazy. I've never been to a Lexus dealer but this might just drive me batty enough to go.