Hybrid engine bay 12V accessory power supply

I’m installing a light bar on my 2023 sequoia hybrid this will apply to a tundra as well. Where is everyone pulling their power supply from? Is there a good spot to pull from in the engine bay or is everyone running a distribution block from the battery. Tried searching but didn’t see much. Thanks.

 

I also couldn’t find anything for tapping into power under the hood.

Here’s what I did instead for a compressor. https://www.tundras.com/threads/arb-compressor-fender-well-mount-for-hybrid.117757/#post-3078766

 

Thanks for the quick reply, good info here.

 

Here is where I found a 14v supply ignition on only. So powers off with truck it was an unused fuse location, trying to figure out how to get a wire through without messing up the lid or voiding warranty.



looking for small water tight through plastic connectors or plugs to run wire through back of lid, as I want to keep that fuse box water tight?

 

I'm looking for the same. 1793 hybrid. Will be wiring up rocker (rock?) undercarriage lights, stealth led bumper and airlift compressor. At this time, the airlift and rock lights will come into under rear seat are via grommet on passenger side and run to terminal block blocks next to battery. Unsure of stealth lightbar yet. I may run them all into the cab near the battery by drilling hole and using a bulkhead fitting.

I have a few weeks until all parts gathered - plans subject to change.

$20 XHF IP68 Nylon Waterproof NPT Cable Glands Assortment 48pcs 1/4", 3/8'', 1/2'', 3/4'', 1'' UL Listed and RoHS Cord Grip Compliant Cable Strain Relief Black

https://www.amazon.com/XHF2018-Glands-Waterproof-Protectors-RAL9005/dp/B07FP6TNHZ

$26 Blue Sea Systems 5045 ST Blade Fuse Block Compact 4 Circuit with Cover

https://www.amazon.com/gp/product/B01BV1MS1K

$10 4 x #10 (M5) Studs Bus Bar, Ampper 4.2" Ground Distribution Block Brass Battery BusBar Junction with Cover for Auto Boat Amplifier and More (Black)

https://www.amazon.com/gp/product/B09T6NNQGV

I am considering consolidating the fuse/relays with the following:

$22 TIKSCIENCE 12V Fuse and Relay Box Block Kit 6 Slots Universal ATC/ATO Blade Fuse Holder Box with 2 Relays Fit for Boat Marine RV Automotive Car

https://www.amazon.com/TIKSCIENCE-Universal-Holder-Relays-Automotive/dp/B0BZCPCNZ4

 

I don’t believe these boxes are watertight.

Here's what I did and notice that I just pushed the wire through the box where all the other wires are going out.

 

like your setup.

I didn’t see much open on that side so I was sticking to other passenger side box since that is where you jump the hybrid from weird little tab to put clamps on cables on to jump.

May not be water tight, but from all the dust under the hood and bugs seems the engine bay isn’t nearly as water tight or dust tight as my 2014 FJ Cruise. Sucks the don’t pre wire AUX switches from factory like others do (bronco, new Tacoma). I’m running ditch lights grill light bar, and E1’s straight off the battery, will use the fuse block for the stealth Amber LED light bar I guess. No more room in the grommet hole I used lol.

 

I ordered these to try.

100pcs Waterproof PG7 Cable Gland Connector Black Plastic Adjustable IP68 M12 Thread Cable Gland with Locknut Rubber Ring for 3.5-6mm Wire https://a.co/d/hem1ExX

 

I too am having this problem... i got the Garmin specifically because i didnt want to run wires through my firewall grommet.... i did some googling because i couldn't believe there isn't a 12v 100+Amp standoff somewhere in the engine bay.... so ... here is what i found....

If i'm reading the below right the middle terminal in the passanger side fuse box under the hood is rated for 150amps 12v DC... and it looks like you could run some 12/14 gauge down through the bottom and back up to a powerswitch (sticking a 125amp fuse in there somewhere as the garmin recommends that amount.

anyone want to confirm my novice wiring diagram reading ?

 

Come on people lots of Hybrids out there someone must be an electrical guru lol

 

What is it you're trying to power? 125 amps running through a 12 or 14 gauge wire is a disaster waiting to happen. 125 amps using 5' of copper wire would need something like 4 gauge.
To be safe you're better off staying away from the factory wiring and fuse boxes for something like what your thinking of doing. Just go straight off the battery. I tapped into an unused fuse under the hood and that was only to have power for my trigger wires on my switches that go to relays.
Here's how I set up my truck for dual air compressors and future electrical mods.
https://www.tundras.com/threads/1794-le-mod-diary.150206/#post-3749222

 

I’m wiring a garmin power switch to a hybrid, there is a terminal in the left fuse box which is fused at 150amps according to a wiring diagram … I can guarantee the factory fuse panel is not getting 150 amps via 14-16 gauge wire, it would already have a 1/0 gauge. So why do you think it’s not a viable option ? Why run 3 gauge from under the back seat into the engine bay if you don’t have to ?

i would run 3 gauge from the terminal in the fuse box to the garmin ideally sitting beside maybe 2ft of wire.

Garmin recommends 125amp for their switch , i think its rated for 100amps in total thought its unlikely i would ever leverage full usage on it.

 

I used a empty fuse for my TRD pro light so no power when truck is off.
But my go Rhino E1 power steps I used the existing hole next to your 12V battery (to direct connect) if you look I believe toward the door you can see it or underneath there is a sticker like thing over the existing hole from factory, fits a 10-14 ga wire perfectly, I just used it and some flex seal and grommet off Amazon.

I used OEM TRD PRO switch but can't find pick here is the ditch light and hidden light bar buttons.

 

This was my initial plan but the garmin power switch should make everything way easier than the oem switches , which ill have to w for sale soon

 

Your original post says, "If i'm reading the below right the middle terminal in the passanger side fuse box under the hood is rated for 150amps 12v DC... and it looks like you could run some 12/14 gauge down through the bottom and back up to a powerswitch (sticking a 125amp fuse in there somewhere as the garmin recommends that amount."
That to me says you're thinking about running a 12/14 gauge wire off the 125amp fuse to the garmin power switch, no mention of a 2ft. 3 ga. wire in your original question that I responded to. If you had included that I would have said for 2 feet at the most you'd only need 10 ga. for 125 amps.

"Why run 3 gauge from under the back seat into the engine bay if you don’t have to ?"
I didn't mention doing that, maybe I missed where someone did. I listed a link to what I did, perhaps you overlooked it, my setup does not go to the engine bay, it stays under the rear seats.
https://www.tundras.com/threads/1794-le-mod-diary.150206/#post-3749222

Running a 3ga wire from the rear seat to the engine bay would still be a little too small. You'd need roughly 12-15' of 1/0 to safely handle 125 amps, for 150 amps and I'd go with 2/0.

On a recent trip to my dealer my cameras and HUD disappeared and were not working. Turns out it was a fuse under the passenger side dash that blew. I was there to pick up parts so I wasn't there just for that. When talking to the master mechanic that found the blown fuse he didn't have an explanation as to why it blew, he asked if I had any aftermarket wiring. I showed him my setup and he told me it was good I wired everything independently from the stock wiring because if he could prove the aftermarket wiring was the cause of the blown fuse I would have had to pay for the diagnosis and time to replace the fuse.
This is why I suggest not connecting to that terminal you showed previously, it's associated to a main fuse box that they could say is the cause of future electrical problems and want to charge you instead of warrantying the repair. It'd be hard for them to associate something connected to the battery and independent of any other circuitry as the cause.

 

Sorry you’re right I miss typed , def wouldn’t run that small a gauge with that much amperage !

that’s a good reason to wire to the battery also I don’t want them questioning anything especially in a hybrid.

last question - if I did run 0/1 gauge into the engine bay , could I find a good ground in the bay or would you recommend running both a positive and negative ? And why ?
One wire might not be so bad. And the hole you went through might be a good spot - I just hate the idea of cutting or putting something through the main harness grommet that I see everyone doing ugh.

 

The best way to ground out anything is the shorter the better. I wouldn't waste the money running a 1/0 ground cable to the engine bay, just too expensive and just another thing that would be hard to check for a short or that could get pierced somehow. There are several areas in the engine bay that you could use as a ground, I've used the stock ground locations for accessories. For something like 150A anything 4' and under would only require a 4ga. Ideally I'd create an independent ground for something this large by going to frame.
The Garmin instructions show the ground cable for the powerswitch going to the battery. Just because this is such an expensive component I checked with Garmin about using a different grounding location. They told me that another could be used but he couldn't answer if grounding to another location could potentially void the warranty. I personally would be fine with not going to the battery as long as I met the needed cable size.
One other thing to consider is that when buying any cables nowadays places like Amazon, EBay, etc. are selling aluminum cable or CCA (Copper Clad Aluminum). CCA is aluminum wire covered in a thin layer of copper. Aluminum wire cannot conduct the same power as standard copper wire. If using something like CCA calculate in a 40% drop, so your 1/0 cable has now gone to 4/0 if using CCA.
CCA heats up more and has a habit of corroding, add electricity to this and the process is enhanced. Add moisture from the air to the mix and the process of electrolysis begins which reduces the cables ability to conduct electricity.
I've made the mistake of using CCA in an off road truck that is not garaged. In under 2 years several of the cables with CCA developed shorts due to the cable splitting internally in the sheathing. The cables were obviously subjected to excessive vibration that contributed to the splitting. Upon pulling the CCA cable and stripping off the sheathing the CCA cable had turned to dust due to electrolysis.

 

I've always had my suspicions of Amazon cables and non brand name electrical... i was going to buy some from some friends who run an audio equipment shop - i'll be sure to confirm they don't use CCA too thanks for the tips !!