yep, both trunk lights aren’t working. Tried new bulbs but nada. So you just replaced that fuse and the door lock started working again 100% of the time? I took a look at your thread, but there’s not any other information offered so I thought I’d ask. Any thing else you can tell me about it? I’ve spent probably 20+ hours trying to figure out the issue but am still scratching my head. Because with mine, all of the fuses in the trunk checked out. I pulled and visually inspected them at first hoping that would be it (I seem to never have the kind of luck that results in easy fixes being the solution when I have a problem like this.) I then checked all fuses in other 3 boxes (except for a handful in the box under passenger side dash), all looked perfectly intact. So I then went back and rechecked them all again using my multimeter this time. Still haven’t found any blown fuses. I may as well just pull the fuse that covers the trunk lights and put in a new one just to be safe. Maybe it’s the slightest hairline fracture in that fuse that’s just big enough to disrupt functionality but not big enough to show up on my meter. I don’t even know if that’s possible but I’m out of ideas.

I had the door panel off of the door with the lock that I’m having trouble with last night, and spent a ton of time inspecting all the wire bundles, connections, door control module, actuator, etc. Everything looks OK from what I could see so for now I’m biting the bullet and plan to take it to dealer Monday.
Kills me a little inside as I’ve already invested at least 30 hours trying to figure this out on my own and save some coin. Not to mention the satisfaction you get when you finally solve a mystery like this. For me there’s few things that feel better in life.

 

It was the fuse panel on the driver's side of the trunk. I don't remember which fuse # but a quick look online shows #8 in the trunk, driver's side. It was one of those, I would check them all again, couldn't hurt and might solve your issue.

 

what document are you referring to when you say the number eight fuse from that box on the driver side of the trunk? I know where that box is, and Ive accessed it, but I can’t find a diagram detailing the fuses in that particular box. I see diagrams for the other boxes, but not the one in the trunk. The number eight fuse shown on the fuse box cap/cover (with 1 beginning at the top left and 2 directly below it in same column, and continuing down vertically through that entire column before moving to the next column and again starting at the top moving down) is the “RL SEAT” which is a 30 amp fuse. See picture ive attached. Do you recall if that was the fuse that you replaced that ended up solving the problem for you? My guess was that the lights inside the trunk would more likely be grouped with the fuse covering “dome lights”, or maybe the one for “tail lights”, or something similar. But that’s purely speculation on my part. Anyone have a diagram for the fuse box in the trunk (for 2013 LS 460, standard wheel base, non f sport)? PS, it’s not provided in the owners manual for this particular year at least
[img alt="Fuse box lid from fuse box located in luggage compartment, on driver’s side right next to the trunk lid automatic opener/closer motor. Trying to determine, which of these, if any, controls the two “194” style interior trunk lights.
"]https://cimg9.ibsrv.net/gimg/www.clublexus.com-vbulletin/1500x2000/img_6646_4793931dbfe7f3b6a064b1b6475d86c69ddd9623.jpeg[/img]
Fuse box lid from fuse box located in luggage compartment, on driver’s side right next to the trunk lid automatic opener/closer motor. Trying to determine, which of these, if any, controls the two “194” style interior trunk lights.

 

Try rr-ecu-b. If it's not any of the fuses in that block, someone a lot more knowledgeable can hopefully help you out.

 

I figured it out! Well the part about the door lock not working half the time at least. I was digging around the fuse box area under the hood and decided to pop some of the covers on the relays and the other type of fuses in there (the ones that are made up of one large piece that contains a dozen or so fuses, I forget what it’s called). Anyway, i happened to notice one of the connectors attached to that part looked Slightly loose so I pushed on it and low and behold it clearly snapped into place, so it was not connected for some reason. Lord knows how that happened. But then my trunk wouldn’t auto close or open, something I had just fixed a week or two ago by replacing the trunk lid lift motor. Frustrating to say the least. I ended up checking some of the fuses in the trunk for a fourth or fifth time just in case and it turns out that reconnecting that plug in under the hood must have blown the 5A fuse labeled RR MPX-B 2 near the top right corner of the fuse box in the trunk because when I checked it this time it was clearly blown. Replaced that one and bingo, the trunk lid opened/ closer once again started working and for the first time since all this began the driver side rear door lock is fully functional again!

now I just need to figure out what’s the deal with starting the car. Oh and I need to verify the trunk interior lights now work, which I’m guessing they will. Just picked up some new bulbs so we shall see. So happy to have the trunk and door lock issues resolved after all the time I put into those . Saved me a few grand from what I would’ve been charged by dealer or even my independent Lexus mechanic, who I’ve lost confidence amd trust in seeing how he told me the door needed a new actuator when in reality it was just a disconnected harness that he should’ve been able to identify and find if his own customer was able to.

 

Hey! Glad you got it sorted.