Power distribution

It's a common problem we all have high powered accessories that we like to have on the battery post.

Alarms,KC's,Winches,amps,E-fans (I have 4!), MSD ignitions and so on with some or all of these things our battery post starts looking like a bowl of spaghetti.

How many connectors have you broken or disconnected when tightening down your terminals?

What is your solution for this mess? I saw a post while back that had a thin thing with a bunch of connectors at the base of the battery post. Kinda cool but a little too thin for my taste.


This is not mine, I pulled it from JF. could be worse

This little guy looks good.

http://www.sonicelectronix.com/item...oogle&utm_medium=organic&utm_campaign=froogle

I use the power distribution block from 90's Chevy/GM trucks. It has 5 posts - 5/16" if I remember correctly. I'll run my heavy alternator lead to one post, a lead to the battery (or hot side of the starter solenoid) then have the rest to take up all my accessories. Best thing is that I usually grab a few when I'm at the pick-a-part and they typically don't charge me for them if I'm buying something else. I grabbed 5 once and they charged me $1.

Get the military "bolt-thru" battery terminals and use a "+ " power terminal if needed.

when I was building massive stereos for a living we used marine grade junction blocks, one 00g input that fed to a tin (i think?) plated 1/4" thick copper bar with 10 studs sticking up out of it, all housed in a oring sealed plastic box. it had a seperate hole in the side for a cable to pass through for each of the connections and a soft rubber grommet that you pierced then ran the cable through.

I'll see if I can find one online and grab a pic.

This is what I used to do my lights. Blue Sea products.

That's pretty cool do you actually ground things too it?


would definitely reduce my use of inline fuses.

hidperf said:

This is what I used to do my lights. Blue Sea products.

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Having that big lead from the battery to that box is just fooling yourself - when the engine is running all of the power is coming from the alternator. The alternator output wire and main battery cable are both smaller than the lead you are using to that box.

That is why I use the junction blocks and route my alternator through the block.

Overkill is better than not killing at all.
atleast he knows there's no resistance from the bat post

Same idea and similar part as above. I love the Blue Sea Systems stuff by the way...

Here's a pic prior to most of the wiring being added. I decided not to use the one with the ground block built in as I felt it would just be a waste of space. I think marine wiring codes require everything to ground back to the power source (probably due to fiberglass hulls?), but in our case most accessories get grounded to the chassis somewhere convenient.



The power wire is fed through this resettable circuit breaker for some added protection.



Power comes directly from my battery terminal.



Here's a view of the whole layout.



As for the alternator issue, mine passes through an ANL fuse (also from Blue Sea Systems), through the PDC, and then to the battery terminal where it ultimately will end up supplying power to my accessories.



And don't worry DieselSJ, I'm not fooling myself. All my mains are 1AWG, my winch uses 2AWG, and the power wire feeding my accessory fuse block is a puny little 4AWG. :laugh3:

fyrfytr1717 said:

And don't worry DieselSJ, I'm not fooling myself. All my mains are 1AWG, my winch uses 2AWG, and the power wire feeding my accessory fuse block is a puny little 4AWG. :laugh3:

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You did it nice.

What I did/am doing -

Battery terminals - I got the solid brass ones from autozone and then used my harbor freight hydro crimper to put #2 crimp terminals on the large wires to the battery and #4 on the smaller one (the PDC feed.)

Power distribution - some of it is in the stock PDC, I disassembled it and used wiring and terminals from a scavenged stock PDC to install my e-fan override relay in here, for instance. The rest, when I install it, will be in another stock PDC mounted in the rear cargo area with my OBA setup and fed via a fused (up in the engine compartment, before all the sharp metal edges that could chafe the insulation and short it out) 8 gauge 50/60 amp feed.

If I ever do a winch, which is unlikely, it will be fed directly off the battery using 1 or 2 AWG. I'll be mounting the contactors in a 100% waterproof plastic junction box near the firewall on the passenger side.

A few other notes - replace the fusible link for the alternator with an appropriate fuse + holder and carry spares. Replace the puny ground wire from the negative battery terminal to the fender with a 4AWG wire and appropriate crimped or soldered terminals. Replace the crappy self-destructing ground braid from the engine to the firewall with a properly crimped/soldered 2AWG cable.

Very cheap, redneck method - blue home electrical junction box from home depot with a solid cap. Take a 1/4" bolt and stack all the terminals on it and clamp it down, then put the cap on. Already has nice holes in the bottom of the box for wires to go in and any stray dirt/water to go out.

I am running dual batteries, so the only connection on the positive side of my batteries is the 2 gauge wire going to the switches, so no issue there. Then the common on the switches comes back to the junction box, also 2 gauge. Everything else, including the alternator, connects inside the box (I think I have alternator, the wire to the stock power ditribution, winch, and both my added fuse blocks, 800W inverter, plus a few random smaller wires). I added front and rear fuse blocks, just the cheap 6 fuse autozone specials. Sure none of it's technically water proof but I've run my jeep through plenty of mud and water, I've had all sorts of problems with stock wiring but none on any of this stuff for the two years or so I've been running this setup.

And with all the concern about waterproofing - getting water on electrical stuff won't neccesarily short it out unless the two exposed surfaces are very close to each other. The sort of extra dirty water we submerge our jeeps in is not particulary conductive. I think the bigger concern is trapped water causing corrosion. I would rather run something with a drain hole in the bottom than something "waterproof", as I've found very few things are truely 100% waterproof, and when you do get a drop or two in there it will cause corrosion. Even if it's waterproof now, after a few years exposure to engine heat, vibration, oils, and mud, they'll start leaking.

SC Rednek said:

And with all the concern about waterproofing - getting water on electrical stuff won't neccesarily short it out unless the two exposed surfaces are very close to each other. The sort of extra dirty water we submerge our jeeps in is not particulary conductive. I think the bigger concern is trapped water causing corrosion. I would rather run something with a drain hole in the bottom than something "waterproof", as I've found very few things are truely 100% waterproof, and when you do get a drop or two in there it will cause corrosion. Even if it's waterproof now, after a few years exposure to engine heat, vibration, oils, and mud, they'll start leaking.

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bold text quoted for truth. You are right, sealing in moisture is far worse than it being allowed to get submerged and then dry off. However, a good soaking of un-sealed battery cables can get water trapped in the insulation that you will never get out. I consider any waterproofing a good preventative measure, but nothing is 100%. As you said though the main concern is corrosion (and accidental short circuits from contacting grounded surfaces of course).

DieselSJ said:

Having that big lead from the battery to that box is just fooling yourself - when the engine is running all of the power is coming from the alternator. The alternator output wire and main battery cable are both smaller than the lead you are using to that box.

That is why I use the junction blocks and route my alternator through the block.

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I used that big of wire because I had it left over from a stereo system install and when I upgrade later, I won't have to remake anything.

Cheap but good so far:

Another XJ Power distribution center and bracket fits just fine, reversed and next to and under the brake booster on DS.

A 50 amp circuit breaker at the front of the stock PDC feeds #8 wire to power the added PDC.

I now have 6 circuit breakers + lots of fuses. Just tape up the wires you don't need (yet), and tuck them inside the bottom half of the added PDC. Looks ok and should be safe.

I'm now running 4 of the relays for-- 2 for L/R low beams, 1 for both high beams, via #12/#10 wire- relays triggered by the original HL wires, and 1 for air compressor.

I just tapped to the battery post on the starter. Keep all that mess off the battery

xjdc12 said:

Cheap but good so far:

Another XJ Power distribution center and bracket fits just fine, reversed and next to and under the brake booster on DS.

I now have 6 circuit breakers + lots of fuses. Just tape up the wires you don't need (yet), and tuck them inside the bottom half of the added PDC. Looks ok and should be safe.

I'm now running 4 of the relays for-- 2 for L/R low beams, 1 for both high beams, via #12/#10 wire- relays triggered by the original HL wires, and 1 for air compressor.

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I am currently doing this, and instead of building my own bracket and drilling more holes, I was wondering exactly how you did this. I don't have the stock air box, so there is plenty of room on DS for me to do this, but don't see how the bracket "reversed and next to and under the brake booster"... pictures would be amazing. Thanks!