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Update: Decided to leave the trunk lid down but not shut completely.
The dash display showed the trunk was open.
My Lexus app messaged that my trunk was open.
20 minutes passed and the dash display turned off.
My battery charger practice moving forward will be to leave the trunk lid down but not pressed completely shut. This way I eliminate the possibility of damaging the charger cable and trunk weatherstripping through multiple future trunk closings with the battery charger connected.
40 minutes later, My Lexus app still indicates a “Vehicle Status Trunk open”. I expect this status will remain until the trunk lid is properly closed.
I left the trunk lid resting on the wire but flipped the trunk lid mechanism with a small flat head screwdriver to the locked or closed position. This left trunk light off and the system reads as closed.
For those who connected charger to the battery. Did you hear buzzing sound from battery? My first time when I used my charger everything was fine, but next time when I connected it after a while I heard that the battery started to produce buzzing sound. Scared enough I quickly disconnected it but battery was still producing that sound. I turned ignition on/off and buzzing sound gone. I checked the battery temperature and ir was same cold as before charge. So I wonder what was it?
For me, it is very important to connect the charger line to the front engine bay, and route that connector to the bottom of the car (in front of the front wheel). All my cars are set up this way. As for the connector end, I use a heavy duty velcro to secure it under and inside the front bumper cover. So when the car is parked for weeks at a time (I travel often), I simply grab the wire and keep it trickle charged without leaving the hood, or the trunk lids open. When done, put the charger lead back under the cover where it would stay secured. I have this same setup on my SUV, M3 and my diesel truck + my a porsche.
I appreicate everyone's comment regardng what alternative methods there are. But this is pointless for me. All can be charged with all doors and lids closed. Installing it in the trunk, there is no way to route the wire clean for quick access. Leaving the lid open to charge may be acceptable to many of you, but for 'many' of us, we are going at a diffierent route. From what I understand, one of the bolts near the rectangular + terminal is also a redundant terminal that can be used as a ring terminal connector for permenant installation. I don't know how to use a volt meter or anything, so I thought I'd ask here.
So going back to my original question: Does anyone know which bolts (see my original photo of the bolts and circled) is 'hot' ? If someone with the right knowledge + voltmeter can quickly confirm this for me, and the community, I would greatly appreciat it! The photo is the post #10 on this thread. Thank you!
I don't have an LC yet (just made an offer on one, though), but if I get one, I'd put a pigtail to charge it right away as well. On the picture above, I'd put the '+' lead on #3... assuming I could put the fuse lid back in place without modification. Like feeding the lead underneath, if necessary. In other words, fully reversible. By the way, where is the battery on this car? In the trunk? If yes, then I'd put the pigtail under the hood, probably using that #3 nut. Equally important is using a proper ground, for proper charging. I don't like not using the battery directly, but being in the trunk, there's no way around that for me. But smart chargers don't like that, for some reason, showing the battery as discharged when left connected for a while. At least that happens with both the G70 and Macan (both with batteries in the trunk/hatch). But if you just charge it, and disconnect it within a few days, zero issues. By the way, I might elect to buy an extension, to put the pigtail by the hood hinge, on the outside, so it's not necessary to open the hood, like I did with my ex-Porsche. But I always like to open the hood, especially in summer, so I'll have to decide when I see how I could route it. And how easy is to open the hood; on some cars it's quite hard, so I'd probably opt for the outside hinge location, if that's the case.
Why 3? Can you confirm that this is indeed the + terminal bolt? I don't mean to doubt you without proof, but since you don't hae an LC, how do you know? When dealing with electrical issues, I need to be sure. Thank you.
I thought I'd revive this thread since we now have the 2024 models, and the fuse box layout seems to be different (maybe not). I have a 2024 Bespoke Convertible. I am trying to figure out a way to permenantly install a trickle charger 'ring terminals' into the fuse box area. Within the fuse box, there seems to be 4 possible connection points for hte ring terminals, but I'm not sure which ones. There are 2 bolts in the box that seems to be connected, and 2 others which seem to be independent of one another. I am also thinking that at least one of the bolts maybe there to hold the fuse box in it's place within the engine bay. Does anyone know which of these bolts maybe used as a positive terminal to trick charge / jump start? I am fully aware of where the physical battery is, and also aware that there is positive 'tab' which can be used to connect an alligator connector. The goal here is to permenantly install a 'ring' terminal onto one of the bolt. I've checked everywhere in the manual, but there is no mention of this at all anywhere.
In the previous models, There was a separate box within the fuse panel wich you remove to expose the bolts. It seems that the newer models just has them exposed. I just don't know which one I need to use to install the terminal. Any help would be appreciate it! Please see the attached pic. I've marked 3 possibilities and labeled them 1, 2, and 3. Which one is he positive terminal bolt?
I am showing all 3 are positive 12-volt ignition off and 14-volt engine running.
I am showing all 3 are positive 12-volt ignition off and 14-volt engine running.
Thank you so much for that! I am not electrically inclined here so please forgive my ignorance. So based on this, we should be able to use any of these bolts as a positive ring connector (of course need to ground it somehwere else on the fender panel), and we should be good to go and be safe? If you believe this, I'd be happy to give it a go with some confidence that I won't blow up my electronics.
I sincerely appreciate you taking the time to run the volt meter for me. I am sure this will help out a lot of people to apply a permenant / elegant solution.
I don't see any reason why using one of the bolts would be a problem. I have worked with the wiring on 3 Lexus and 3 Acura's, so all Japanese cars with no problems. Not that I have ever used a trickle charger, but if the manual for the LC and LS shows using the engine bay fuse box to jump start the car, I would do this to my LC. I used one of the grounded bolts by the fuse box for my Beat-sonic front camera install so you can go there for your grounding ring (clean off the paint).
If possible you could stop by a Lexus shop and speak to the head mechanic.
I'm not trying to come over as a 'know-it-all' because obviously, I don't, but I'm a time-served electrician by trade. When the factory closed down I became a telephone engineer on BT, and after a back injury LED to medical retirement I'm now self-employed doing computer repairs. I'm also a licenced radio ham and dabble in electronics as a hobby. I mention that, not to blow my own trumpet, but just to explain that I've been in and around the electrical/electronics fields for more than 40 years.
In my humble opinion (and this goes for both jump starting and charging), 12V is 12V.
It just doesn't matter whether it's at the front or the back, it's still 12V and all you're doing is piggybacking one 12V source onto another 12V source.
The only thing to worry about is to make sure you connect with the correct polarity.
I don't see any reason why using one of the bolts would be a problem. I have worked with the wiring on 3 Lexus and 3 Acura's, so all Japanese cars with no problems. Not that I have ever used a trickle charger, but if the manual for the LC and LS shows using the engine bay fuse box to jump start the car, I would do this to my LC. I used one of the grounded bolts by the fuse box for my Beat-sonic front camera install so you can go there for your grounding ring (clean off the paint).
If possible you could stop by a Lexus shop and speak to the head mechanic.
Copied this from another LC forum and I agree.
Given the proximity and easier wire routing, I think in my case, it woud be best to use one fo the strut tower bolts. For now, I'll just grab a cheap battery tender and use it with a ring terminal + SAE connector and route it below the engine and have the SAE end accessible from below the feder / front bumper cover. SAE end will stay secured via velcro tapes under the car. Once I decide to upgrae to a LiPO4 battery, I'll invest in a nice CTEK unit, but for now I'll just use the cheap battery tender unit I have for the lead acid batteries. I'll try this next week after Christmas and report back regarding the results. It'll be a project since I'll most likely have to drill a hole into the fue box, install the wires, then seal the hole as best I can using silicone. Once this is done, then it's done. Just reach under the car, pull the plug, connect it. Done. No shuffling through the trunk or leave anything open (trunk or hood) while charging.
It is highly likely that I'll upgrade the battery in the near future (next big sales event) to the Lithium one (LiPO4). Does anyone know if this charger will charge both the LiPo4 and the lead acid? I do know that only specified charger is required for the AGM batteries, but as far as I knew, all lithium chargers will also charge lead acid. Here is the unit I'm considering. It doesn't specifically say lead acid, so just being cautious..
I left the trunk lid resting on the wire but flipped the trunk lid mechanism with a small flat head screwdriver to the locked or closed position. This left trunk light off and the system reads as closed.
My tender is connected in the trunk with a quick disconnect to the battery, I ran the wire from the top of the trunk, left corner near the black trim/back window the rear driver side katana roof blade so the wire wouldn't 'pinch'. I can close the trunk fully and the battery will charge with zero issues and no 'trunk open' indicator in car or on my Enform App.
The cable rests lightly against the car but I also placed a MF towel there so it isn't actually on the paint itself.
If you'd like a picture I can take one or two if it helps.
mess with the engine electrics on a > 100k car ?
might be wiser still to go to your certified lexus mechanic, who receives special training to work on our babies, and simply ask him for the correct way of doing this.
those of us with advanced EE degrees would probably agree.
11-20-23, 10:23 PM
