electdroid

The brake lights on the trunk lid of my 2007 ES350 don't work. I discovered this while installing a trailer light adapter. I did not install a bralke/tail light bulb properly and got the warning on the dash but while checking it I found there are brake lights on the trunk lid but they do not work and do not activate the dash warning light. They are wired and have good bulbs but no voltage when the brakes are applied. Were they not intended to work? Is there a fuse for them? Why no warning on the dash? The brake/tail lights in the body and the one in the back window work ok.
Any ideas? Seems to me that more is better when it comes to brake lights!

nevernu

i think the lights in the trunk lid are backups and taillight, the only brake lights are in the body. turn ur headlights on and the taillight should come on

electdroid

Yes, the lights on the trunk lid are back-up and tail light but the tail light bulb has two filaments and it is wired as a brake/tail light. Unfortunately, the brake light part of the bulb doesn't work...

nevernu

just checked on my 07, i guess mine is broken too cause it only acts as a tail light, i haven't checked the filaments

if u check the wiring diagram p3. you will see the the tail (trunklid) is 1 filament and the tail/stop (trunk body) is 2 filament.

electdroid

Thanks for that nevernu but unfortunately the wiring diagram is wrong. The trunk lid lights on my car are dual filament bulbs, the same as the body stop/tail bulbs.
They have three wires going to them--ground and one for each filament. I'm going to have another look tomorrow to see if I can trace the wiring or at least check the wire colours.

Nutsplats

The brake lights and tail lights are all 7443 bulbs which is a dual filament bulb. There are 4 bulbs across the back which are your brake and tail lights. 2 bulbs on the outer part not on the trunk lid and 2 bulbs on the inner part on the trunk lid. All 4 light up as tail lights. When you hit the brakes only the 2 outer bulbs will light up. Even though the 2 inner bulbs are a dual filament only one filament lights up. The 2 inner bulbs on the trunk lid do not light up as brake lights they are tail lights only.

speedkar9

I wonder if you could rig them to work as rear fog lights?

mj1401

My passenger tail light would often glitch on and off when driving over bumps and rough roads. One day it went out one day a few months ago and I went to Walmart to get a replacement (7443). I changed out the bulb and it worked, but the warning light on the dash didn’t go off. I waited until a few days ago to replace that same bulb to see if it would make a difference and shut off the warning light. I didn’t. In fact, the passenger tail light stopped working altogether. I checked the fuse with a circuit tester and the fuse had no power. It is fuse number 15 according to the fuse box diagram for my vehicle. I replaced the fuse and still no power to it. What I find funny is that that same fuse supplies power to the Front and rear side marker lights, tail lights, and license plate lights…all of them work except the tail light. I took it a step further and got a brand new replacement pigtail connector (that the bulbs sit in - see the photo below) and it still doesn’t work. I went to pull-a-part and took the fuse box off of a 2007 model that matched exactly, replaced it with mine without any issues, but still no power to that fuse. All of the fuses and relays under my hood are working except there is one missing (R4) and it has always been missing I think…and all of the fuses under my driver dash are working except #15, #16, and #31 (all in proximity to one another…tail, panel, and mirror heater). I don’t have any info about a pin diagram for the wiring harness to see if maybe the wire itself shorted out and I’m not sure I could even understand it if I did. I don’t know what to do at this point.

TCoolest2

Well with some of your diagnostic I think you have localized that it's more specifically a circuit relating to your tail lights. I imagine from the age maybe a wire has gotten corroded or inside a connector somewhere. I can try to look around for a diagram when I get a chance. In fact you say the passenger side, the ES and some other lexus models are known to collect water in the trunk near the wheel wells. There is some component there, I forgot the name, that allows moisture and can affect the amplifier for some audio systems, maybe it's affecting the rear tail light there?

mj1401

Im thinking it’s coming from under the hood from the fuse box to the other fuse box under the driver panel. I don’t know where to find a diagram for the pins to isolate the exact wire without changing out the whole thing. The driver side fuse box in the cabin isn’t getting any circuit power at all. I would appreciate any help!

nevernu

this is the fuse wiring and fuse layout if its any use