Which gauge wire should I use?

So I am installing a Blue Sea #4366 panel in the bed. It will mainly be used to power our electric cooler (while driving) on camping trips. I ran an 8 gauge from the engine bay to the bed. The power lead based on where the panel is mounted is about 15 feet. The problem with the 8 GA is finding the connectors for the panel. I would have to order them. I emailed Blue Sea and they said that based on 2.5 to 3 amps and a 30 foot run from the battery to the panel and back, a 14 guage wire would be fine. That seems small to me. He also said that the 8 GA will work as long as I get the right connectors and support the wires so that they are not pulling on or putting tension on the terminals. I will have an inline breaker near the busbar in the engine bay as well. What gauge would you guys use?

https://www.bluesea.com/products/43...er_12V_Socket_Dual_USB_Charger_Mini_Voltmeter

https://icecofreezer.com/products/i...prH0Eb7r3SytkNzCpE_kIG3yijuL7Sm4aAgvmEALw_wcB

@dittothat @mZiggy tagged since you guys were in the other thread

 

Blue Sea Circuit wizard says 12GA at 15A 15ft, I would run 10Ga, but if the 8 ga is run, just step it down to whatever size the panel will handle. Then it's basically a 1' run.

 

I forgot the ground back, 30 ft. as you mentioned, but that's at 15 amps, 8GA is recommended for 30ft. If the round trip is already in there, I would still just step it down to the largest that fits the panel.

 

He said that the 8 GA would work if I get the terminals. Amazon has them. Do you think the 8 is too big for that panel?

 

You cant be too big really. It's just more expensive. Too small is where things get hot. No problem if the connectors work with 8 Ga

 

I have no idea what amps the IceCo pulls...that's why I linked it for the guys that are smarter than me lol. So the ground should run all the way back to the engine bay as well? I was thinking about grounding it to the frame under the bed somewhere.

 

You can ground to the frame if it's a good ground. And then your run is done to the battery. Just make sure it's a clean solid ground to the actual frame. I ground most things back to the battery, but my amp with 4ga is on a frame ground.

 

Ok so if I order those connectors, it will be fine to use the 8 gauge 15 foot run for power and also ground to the frame under the bed (about 7 feet) without having to run it back to the engine compartment?

 

As long as the ground is good and not prone to corrosion. And, as long as the fridge directions don't say don't do that - I think my switchpro says that. If you want to never worry about it, ground at the battery and forget it. If that fridge does pull close to 15A, which I doubt, stay with 8 ga everywhere.

 

I did pretty much the same thing as you using this

$78 8 Gauge 8 AWG 37.5 Feet Red + 37.5 Feet Black Welding Battery Pure Copper Flexible Cable + 10pcs of 3/8" Tinned Copper Cable Lug Terminal Connectors + 3 Feet Black Heat Shrink Tubing

https://www.amazon.com/gp/aw/d/B01M9JK00R?ref=ppx_pop_mob_b_asin_title

I put a fuse panel/bus bar in a little project box with the 12v panel on the side of the box. I connected the 8 guage to the bar directly then put a 10 amp fuse on it. The 8 guage going to the engine bay is connected to a fuse panel next to my switch pro with a 15 amp fuse. Overkill but that's how I roll. I used 14 guage on the 12v panel to the bar in the project box.

I have the same fridge as you and in 100 degrees my jackery never showed the fridge getting anywhere near 10 amps.

 

4 to 5 amps is pretty regular, I might have seen 7 for a second but never seen more.

 

My iceco draws 4ish amps when the compressor is running

 

sorry @Tundra234 just seeing this. I would run 12awg and call it a day. If you do this you’re covered for the full 15a of the circuit. 14awg wire would probably be OK but might start to get a little warm if you’re pulling the full 15a. So, either 12 or 14awg, and as straight a line back to the bed as possible to keep it as short as possible.

also, when you get your blue sea I’d recommend picking up these if you plan to use that outlet dedicated for the fridge:
ARB 10900028 Threaded Socket/Surface Mount Outlet

$15 ARB 10900028 Threaded Socket/Surface Mount Outlet

https://www.amazon.com/dp/B00NIOBC0C

ARB 10910076 Power Cord Cable for ARB Fridge Freezers DC 12V

ARB 10910076 Power Cord Cable for ARB Fridge Freezers DC 12V

https://www.amazon.com/dp/B01EHUO8Y2


it provides a threaded connection for the fridge power cord and makes it nearly impossible for it to come unplugged. You can swap the plug from the arb housing over to the blue sea.

edit: use @Taco-Spike chart. Fridges aren’t super sensitive electronics so you don’t need to account for voltage drop. And I’d run your ground from the blue sea panel back to the battery. As I said above I’d do 12awg. Iceco pulls no more than 3.5a

 

I have this panel and a surface mount for it (which isn't waterproof but does allow it to be a bit more contained. It's nice. I haven't installed it yet.
I intend to run 8 gauge as well. This would be for my 2016 Tacoma I think, though I may do similar in my 2002 Tundra or I might stuff this one in the Tundra and not the Tacoma, not sure yet.
@alb1k likes to run grounds back to the engine bay? I don't do that. I am currently using a frame ground for my rear setup in the Tacoma and intend to do the same in the Tundra. Above both rear wheels in the Tacoma is a nice solid frame ground with bolt. Unbolt, add ring terminal to 8 gauge, resecure. It's a little hard to get to but you only need to do that once and you're good for a long time, plus there's no worry about shorting a live "ground" wire

Now, as to how to get 8 gauge power and ground turned into something usable, that's a legit question/concern and one recently "solved" for me with this. I have 3 of them, one for each truck, though I haven't installed any yet. It's the right solution for me. Granted that brings power all the way to the rear rather than just to the front of the bed, but it's super useful to have power in the rear corner for other types of accessories as well and I'm a fan of it:

https://www.tacomaworld.com/threads...-drivers-side-taillight.782761/#post-27995896

If the desire is to run the shortest power lead possible, I'd still use some sort of fuse holder to take the 8 gauge ring terminal on one side and turn it into a 10 or 12 gauge lead on the other side which can then feed directly into the blue sea. Those yellow female terminals won't crimp on 8 gauge well at all and the 8 gauge is too much beef to direct connect.

It's totally OK to have more than one fuse involved, the fuse at the battery really protects the cable for the most part while the fuse at the destination is protecting the output. You just want to make sure it's semi accessible so you can change it if you need to.

For car audio we often do stuff like this, fuse 100 amp at the battery, feed to distribution block, then 40 or 50 amp fuses to each individual amp. Since it's usually easier to run a single large gauge cable into the cab than multiple slightly smaller gauge cables, a bit bigger diameter makes a significant difference in current capacity / lower resistance.

Hopefully some of this helps? I especially like the work user "switch" on TW has done to make small 3d printed boxes for the fuse blocks. He has an engine bay version too but that's very Tacoma specific. We could probably get him to do something for a 4 circuit super mini fuse block, though it sure is nice to stuff power and ground into one spot and then feed out. And the taillight is super convenient.

 

I think the current may be limited by the push on spade connections and one problem with the heavier 8ga wire might be the strain it puts on the circuit board. If you bend the wire properly and secure it close to the terminal that will help quite a bit. Another option is to strip the 8ga with a #10 stripper and solder the wire to the female spade.

 

I'd employ something like this to get it done with the easiest path, I believe it's what is used in the switchpros power lead.

Run 8 gauge in via ring terminal and then 12 gauge out to the blue sea unit so you get a nice crimp on the female. The extra fuse doesn't hurt either.

 

Use welding cable and remove all doubt.

 

He could run his fridge, and all his friends fridges, too.

 

I ended up removing the 8 gauge and dropping down to 12 gauge. Will it still be fine to run the ground to the frame under the bed somewhere?

 

Will be fine. No worries there

 

Now all I have to do is find a ground back there lol.

 

That looks sweet. Ground it yet?

 

Damn, that’s clean. Nice work, George. Better than anything I’ve done lol

 

Yes....up by the battery.

 

If you haven't attempt it yet, there's a ground on the passenger side kick panel. Quite a few grounds there but I've done 2 grounds to that area.

 

The ground I mentioned before, on my 2016 Tacoma.

 

Right now it's grounded to my Blue Sea fuse block.

 

The absolute best place to ground an auxiliary circuit is where the battery grounds to the vehicle, not actually at the battery terminal. This ensures it's reference potential is absolute zero like that the truck. If you are grounding to the Blue sea block, make sure that block ground wire is going to the battery-to-vehicle ground.

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