Auxiliary fuse box in back

kolelt

New member
I have a RFRM 10 relay fuse/relay box. It's pretty big and there's not much room under the trunk. Maybe if I move the coolant reservoir and put the battery side ways I could possible mount it under hood. But I was thinking has anyone installed a aux fuse box in the back ? My only concern is running a power wire all the way from front to the back. Roughly 8-10 feet. Is this safe ? What gauge wire would you recommend if so ? Box is rated for 100amp.
 
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My only concern is running a power wire all the way from front to the back. Roughly 8-10 feet. Is this safe ? What gauge wire would you recommend if so ? Box is rated for 100amp.

It's perfectly safe as long as you run the wire back there the right way. It's done for amplifiers all the time. I have an inverter in the storage bin on the passenger side in mine, and an amp under the seat. Pulling the wire back there is pretty easy.

If you're planning on using the full 100 Amp capacity (and that's a lot, so I doubt you are) you'd need to pull at least a 6 gauge wire, but I'd bump up to a 4 just to minimize the voltage drop.

The easiest thing to do is buy a 4 gauge amp kit like this one:

http://www.amazon.com/Stinger-SK464...d=1462561901&sr=1-14&keywords=4+gauge+amp+kit

You need a fuse on the wire as close to the battery as possible (within 8-12" is good). That prevents burning the truck down in the event of a short under the carpet or in the back.

There's a grommet on the driver's side that you can poke the wire through, and run right down the side under the door sills. There's a really nice wire track under there with clips that will keep it in place.

I don't have good pictures of the installation, but here's where I mounted the fuses. There's a threaded hole already there:

(Note: I used black wire because it was all the shop had on hand, but I actually like more than the red because it looks more OEM)

23283668815_3ac6eeb0ec_b.jpg
 
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I have a RFRM 10 relay fuse/relay box. It's pretty big and there's not much room under the trunk. Maybe if I move the coolant reservoir and put the battery side ways I could possible mount it under hood. But I was thinking has anyone installed a aux fuse box in the back ? My only concern is running a power wire all the way from front to the back. Roughly 8-10 feet. Is this safe ? What gauge wire would you recommend if so ? Box is rated for 100amp.

I have a 1 ga running into my rear storage box in the back. I ran mine along the frame and came up through the grommet near the rear shock mount. Like Jeremyc74 said, it's perfectly fine as long as it's fused and you run it carefully, not putting it in a place where it will eventually get worn or cut on something. As far as what gauge to run, I use something like this chart. It's always better to use thicker than you need. I would use minimum of 8ga for 10' of 100a.

https://www.google.com/search?q=aut...AUICCgB&biw=320&bih=492#imgrc=wJ551k9zCGT_XM:
 
Yea I currently have all of the seats and carpet out of the truck. So it's easy. Having it under the hood would be nice and "cool" but it's pretty big aux box. With 10 relays !! In my head I have it planned but executing it is another story.

I like the frame rail idea. That's neat. I was planning on cutting into the plastic rear trim so the bussmann can be exposed just enough to access the relays and fuses. More I think about it the more I like the idea.


I'm planning on having a amp/sub on the passenger side. That's why I'm choosing the driver side as the location for aux box.
[MENTION=113639]Mgyver1[/MENTION] mind sharing photos ?
 
Where did you get the fuse box from?

Sent from my SM-N910V using Tapatalk

This is my box, has 10 relay and 10 none relay fused.







He sells a 5 relay box on eBay

Universal Waterproof Fuse Relay Panel Distribution Cooper Bussmann Off Road | eBay

However he made mine upon request. Total cost was $230. Considering the tools and resources you need. It's worth it to me. I wanted the 10 relay because go big or go home.

His email is [email protected]
Facebook https://www.facebook.com/Waterproof-Fuse-Relay-Box-1391112501215493/

And someone did a nice review here on the 5 relay

Waterproof Fuse Relay Box Review and Install - 4WAAM


I am looking forward to installing it and running my lights and such of it. For switches if you want constant power. You can use 1 of the 10 no relay fuses power outputs.

So far in my head I have few locations for this box.

Move the battery sideways and mount it where the 2nd battery would.
Mount it on passenger side near intake
Mount in the back somewhere
Mount it under the back seat where the stock jack is. Which the stock jack is useless on lifted truck if you ask me.
 
Yea I currently have all of the seats and carpet out of the truck. So it's easy. Having it under the hood would be nice and "cool" but it's pretty big aux box. With 10 relays !! In my head I have it planned but executing it is another story.

I like the frame rail idea. That's neat. I was planning on cutting into the plastic rear trim so the bussmann can be exposed just enough to access the relays and fuses. More I think about it the more I like the idea.

If you already have all the interior out, I'd run it inside. That will keep it out of the elements, and prevent damage from wheeling or road debris.
 
If you already have all the interior out, I'd run it inside. That will keep it out of the elements, and prevent damage from wheeling or road debris.

I understand. Inside sounds easier to install due to size. However the box is basically 100% waterproof. Even the wires going from the fuse box have little rubber seals around the female/male connectors.

The rear passenger side is perfect. But then it leaves me scratching my head where to install sub and amp. As I want to leave as much trunk space as possible. Anyone ever install sub/amp over drive side fender ?
 
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I got the same box, I installed it on the passenger side of the engine bay after I moved the ABS fuse box over. I used an existing threaded hole and the same bolt to move the ABS fuse box over.

7865deb0ebfa3c3b445060edc8893b88.jpg

3851ce490da9ffe09d5d94ac67050c25.jpg


Sent from my LG-H830 using Tapatalk
 
I got the same box, I installed it on the passenger side of the engine bay after I moved the ABS fuse box over. I used an existing threaded hole and the same bolt to move the ABS fuse box over.

I guess you don't have Cruise Control?
 
Oh that's pretty cool man. I installed mine in the back. Where the OEM jack goes. I actually like it better because it eliminates all the wires out of the engine bay.

I guess I wouldn't mind installing it in the engine bay. At the time I had no place to put it. It's huge !!

How are you liking yours ?

 
Oh that's pretty cool man. I installed mine in the back. Where the OEM jack goes. I actually like it better because it eliminates all the wires out of the engine bay.

I guess I wouldn't mind installing it in the engine bay. At the time I had no place to put it. It's huge !!

How are you liking yours ?

I like that location! It works for Cadillac and BMW, easy to access, central to many things. I am considering running a tube under the carpet to make fishing future wires easier. Something similar to these.

Cable Raceways | Surface Mount Raceways | Latching Raceway | Wire Guards

I just don't want to have to pull up the carpet every time I add a circuit, cuz no matter what I say now, I'll think of something else later!
 
Oh that's pretty cool man. I installed mine in the back. Where the OEM jack goes. I actually like it better because it eliminates all the wires out of the engine bay.

I guess I wouldn't mind installing it in the engine bay. At the time I had no place to put it. It's huge !!

How are you liking yours ?

It is huge! I didn't expect it to be that big! I was in a dilemma on where to but it. But I figured engine bay is easier for me since most of my accessories are out in front right now. I like the location you chose to though!

Sent from my LG-H830 using Tapatalk
 
I like that location! It works for Cadillac and BMW, easy to access, central to many things. I am considering running a tube under the carpet to make fishing future wires easier. Something similar to these.

Cable Raceways | Surface Mount Raceways | Latching Raceway | Wire Guards

I just don't want to have to pull up the carpet every time I add a circuit, cuz no matter what I say now, I'll think of something else later!

That's why this aux fuse box has 10 relays and all pre wired. You just tap into the wires and your good to go. Eliminates the need for prewires harness.

All my wires are ran where I want them.
[MENTION=136553]mikeySA[/MENTION]
I ran my wires like this: I ran 5 wires to the back behind the rear pannel for rear
accessories such as rear led bar and whatever else for future. Then ran 5 wires to the front through the gromet. For front led bar and whatever else.

Switch wires and power wires are ran to the front under the head unit.
 






I have 2 bussmann breakers. 1 breaker @100amp for the bussmann 10 relay box. And another breaker for a small fuse box under the hood for small amp stuff. Everything fits perfect. Was a pain in the ass to mount them. Had to stick my through the little hole in fender. Used ss alen key bolts. With rubber washers on both sides. So no water penetrates and causes rust where I drilled the holes.
 
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That's why this aux fuse box has 10 relays and all pre wired. You just tap into the wires and your good to go. Eliminates the need for prewires harness.

All my wires are ran where I want them.



Switch wires and power wires are ran to the front under the head unit.

No way that could work for me, I wouldn't know ahead of time what gauge, and what set up I would want to use. I prefer to switch ground on the relay, but that isn't always the expedient way to go. And I don't like to extend the wires, I'd rather just run the wire from the relay to the load with no splices if possible.

I would just add as I go, but I still like your location!
 
No way that could work for me, I wouldn't know ahead of time what gauge, and what set up I would want to use. I prefer to switch ground on the relay, but that isn't always the expedient way to go. And I don't like to extend the wires, I'd rather just run the wire from the relay to the load with no splices if possible.

I would just add as I go, but I still like your location!

You can. You can either build your own box with proper length. Or there's a guy of eBay who builds them. And you can ask him to make what ever length you want. The box has 10 relays all prewired. It has 10 12gauge wires for accessories (such as lights , CB radio or whatever )more then enough gauge. Then 10 14gauge wires for power. And 10 16gauge wires for switches. You basically run your wires to where you need. And you run your 14 gauge power wires and 16gauge switch wires to where your rocker switches will be. And that's it. You hook it up to your switch. The relays are fused and so are the 14gauge wires. The 14gauge wire is just a wire to trip the relay.

Everything runs directly of the relay. Just everything is in one location.

It is completely safe to extend a wire if done properly. Soldering or proper size but connector is safe to use. (Saying this is like saying it's unsafe to make a junction box for romex wires that run inside a house, which is more dangerous than automotive wires) I've done electrical work, and there were plenty of times where you must extend a wire or make a junction box. Even on THICK wires that have a lot of juice running through them. if done properly you don't lose anything.

The box is rated for 100amps

You can see the backside of the box. By scrolling down in this link.

Waterproof Electrical Boxes?
 
I needed to extend my wires because I ordered the box by thinking I was going to install it on my engine bay. And the wires would have been long enough. But it didn't end up that way. So I needed to extend them. And I choose to use quality but connectors with marine grade shrink wrap over it. Even though the it connectors were water proof to begin with. But I made sure when stripping the wire I didn't lose any strands of wire.

You can see work here. I took my time and I did it safely. And I am very proud and stand behind my work.

http://www.toyota-4runner.org/3rd-gen-t4rs/170655-koltlt-97-sr5-build-thread-4.html
 
You can. You can either build your own box with proper length. Or there's a guy of eBay who builds them. And you can ask him to make what ever length you want. The box has 10 relays all prewired. It has 10 12gauge wires for accessories (such as lights , CB radio or whatever )more then enough gauge. Then 10 14gauge wires for power. And 10 16gauge wires for switches. You basically run your wires to where you need. And you run your 14 gauge power wires and 16gauge switch wires to where your rocker switches will be. And that's it. You hook it up to your switch. The relays are fused and so are the 14gauge wires. The 14gauge wire is just a wire to trip the relay.

Everything runs directly of the relay. Just everything is in one location.

It is completely safe to extend a wire if done properly. Soldering or proper size but connector is safe to use. (Saying this is like saying it's unsafe to make a junction box for romex wires that run inside a house, which is more dangerous than automotive wires) I've done electrical work, and there were plenty of times where you must extend a wire or make a junction box. Even on THICK wires that have a lot of juice running through them. if done properly you don't lose anything.

The box is rated for 100amps

You can see the backside of the box. By scrolling down in this link.

Waterproof Electrical Boxes?


I never said it was unsafe. I've been doing electrical work since I was in trade school, 36 years ago. I simply said I "prefer" to run one wire all the way to the source or load. The wire I run today might not be available to me when I decide to add the circuit 3 years from now. I hate changing colors or style mid circuit. A/C circuits use Black White Red and Green, or bare copper. And the wire is pretty standard. Automotive stranded wire has thousands of variations. This would NEVER work for me, because I might decide I want to use a load that requires heavier gauge, or the switch circuit might need a double pole double throw, or I may combine two circuits or divide one at some point. As I said in the first response, I prefer to switch the negative side of the relay and use 18 or 20 G for the switch circuits like the OEM's do. Again, just a preference.

It might work fine for you, or others, just not for me. And it looks like you are doing a great job I might add. I don't doubt your harness will turn out great. For what it's worth, 20 years ago I'd have had no problem with that style. I'm not against it completely, it's just not what I would prefer.
 

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