Electrical - Ground location from bed

Can anyone provide input on the best location to ground to, from the bed? 3rd Gen.

Setting up a solar/battery system with most components located in the bed. I need to run a ground wire from there. I've read the negative post on the battery is the best spot, and grounding to frame is also ok. I need to run 4awg wire which is expensive, so looking for closest acceptable spot to the front of the bed.

Any suggestions on best or most convenient location to ground to? I stuck my head under the truck but didn't see any obvious spots where the frame had bolts I could remove and post a wire to.

Thanks for any suggestions

 

Take off the driver tail light. There are two m6 studs sticking out on the inside. Just get a matching nut.

 

Edit: and I wanted to name drop parts-express.com for your cable needs. I've bought a bunch of wire and cable from them and have been absolutely thrilled with it. Their prices on spools of zip cable are great too, that might interest you. It's way cleaner than running two wires per connection. Grab some expanding loom off Amazon too, cut it with a hot knife or soldering iron smoothing tip so it won't fray. Use butyl to seal holes in grommets or body plugs.
https://www.parts-express.com/wire-cables/bulk-wire-bulk-cable/zip-cord
What I wrapped by 4ga power and ground with to keep them together:

$21 Keco 100ft – 3/4" PET Braided Expandable Cable Sleeve – Wire Sleeving for Audio Video and Other Home Device Cable Automotive Wire - Black

https://www.amazon.com/gp/aw/d/B07K1YPMP8?ref=ppx_pop_mob_b_asin_title
The details like sleeving, tape, butyl and adhesive heat shrink really clean it up.


Edit #2, advice boogaloo: if it's a low power circuit like a solar maintainer, be sure to clean up and seal contact points and soldering the connections isn't a bad idea. With high power comes a higher tolerance of increased resistance. A 12v, 2a charge will get murdered by a long run of cable and a touch of corrosion.

 

There are several bolts to choose from depending on where you want to bring in your wires. I used one the frame behind the passenger rear tire on my first build. My current build I found one just in front of the the fuel tank. Access is from the top of the frame. I believe it was a 10mm bolt. I brought in 4awg wire in the front driver corner on the side of the bed.

scroll down for my set up.
https://www.tacomaworld.com/threads/fwc-project-m-project.650163/page-2

 

Thanks guys! I actually had the driver side rear tail light off already for something else, so I used TacoMike's suggestion. Had exactly the right amount of wire to get there

 

I would use any bolt available for ground if the circuit was of minor amp requirements, but being that you are placing a 4awg wire for an added battery, BK should be your choice. Just saying...

 

OK, so I think I found BK. Does this look right in the pic below? That is the leaf pack, shock and tire for reference. BK would be the stub wire branching off near the center of the pic.

What is the reason this spot is better than the tail light spot TacoMike suggested - since its frame rail as opposed to a body support?

Also, should I mount using the existing bolt there, or is it ok to attach through the hole to the left? Thanks!

 

OK, new opinion; yes the frame is a better place for a ground for a high current device, it simply acts as a larger conductor and your #4 is a LARGE conductor. From the picture I see two bolts coming through the frame near the brake line, just use a ring terminal of the proper size with a few washers and a nut and you are set. I may also see another bolt through the frame near the center of the picture, but the detail is so bad I can't be sure. Possibly that one as well. Tail light location is suspect as body panels don't always need to have an electrical ground and when they do might not keep a good connection for the life of the truck. You are looking for a low resistance connection back to the battery and one that is not subject to corrosion so star washer(s) and a few flat washers to even out the bottom of one of those bolts. The only problem with the existing through hole you mention is getting a good clean bond in a difficult location to work in.

 

Yes.
Here is a little better pic.

AMPS to handle.

If you use hole next to it you would need to scrape the chassis paint for an excellent bound. I'd stay with the original bolt.

 

Thanks for the extra input everyone. I moved the ground to the single bolt shown in the pic above, now with red arrow.

It was a pain to access and undo, but not as much of a pain as the other two with blue arrow would have been. Those two attach brackets. The one I used attaches the stub end of a wiring harness as caribe's photo shows. It was just a tight spot to get a wrench or a ratchet into with ribs of the bed right there.

Everything is good now. I still had room to run the 4 awg wire through the gap in the front driver side bed corner up top. Again just enough wire length for this run.

 

Post some pics of the cable run...

 

Haha, it's all on top of the frame rail out of sight. Not much to take a picture of.

 

hi there i understand it's an old post but i am in the same project as yours few years ago. i need to know where exactly did you poke in the wire into the truck bed. My plan was to enlarge the tiny hole in the driver side front bed floor which is probably there to evacuate accumulation of water. But i rather not drill a hole in the bed if possible. the hole needs to be big enough to run my positive and negative #4 awg wire. thanks for the help

 

I have a 2019 Taco. At the front of the bed there is a gap between the bed rail cap and the bed on each side. I ran the wire through that.

The hole you mention on the front bed floor is a drain hole. Personally I wouldn't use that to run a wire through because you can get water accumulate there if it's blocked. I blocked mine to help seal from dust/water intrusion and I get water pool there every time I wash my truck spill a jug of water.

 

Only thing to add to @evdog reply:
Some of those who have enlarged the driver's side bed hole have hit, with the drill bit, the gas hose immediately below the hole on some models creating a much bigger problem.

 

Ok thank you I will use the cubby on the driver side bed instead. So you don’t recommend to fill in those little drain hole before to install my plywood floor? I was thinking doing it

 

You haven't said what you are doing in any detail; Do you have a top, a cover? Just what is going on?

I can say these Tacomas leak from many places. The corners of the bed where it has been discussed running wires, the joint between the metal and plastic bed rails, the very open joint between the composite bed and the fender metal, this is the worst for me with my fender liners removed. You will have water intrusion into the bed, how much depends upon what you are doing and the steps you take to mitigate. And what you wish to do to get rid of the water that accumulates.

EDIT: In case you are worried about water coming up from the street through said holes, I have not had that happen.

 

Yeah sorry for the lack of detail. Yes I have a topper and I am building a truck camper and it is already seal on the top corner where you wired yours. All the tailgate area will be sealed. I am gonna have a plywood floor treated so that is why I am asking what I should do about those little drain hole in the bed. Thanks

 

I don’t think it will matter in the long run. Leave them open and in time they will clog with small debris.