Need your help and advice: Adding electrical stuff...does this make sense?


Don’t get me wrong, I bought an S-POD for my JKU and I’m something like 95% happy. I would get another in a heartbeat. But... I’m running two radios and 2 different light setups. I’m building in my air compressor. For a long time I just clipped it to the battery when needed, so I’m not sure if I will add it to the SPOD. Winch is direct to battery. My fridge goes direct to a sub switch panel in the rear that includes 3 other light setups. You wouldn’t want a fridge on a switch, at least I didn’t, so direct is the way to go.

Building the rear panel wasn’t hard and the tools aren’t expensive. If I was staring down the costs you are considering, I would just start with one good large battery in the stock location with really good cables to it.

The skills aren’t hard to learn. Fuses are your friend, and this community is very helpful. The problem here is that there are usually multiple acceptable ways to do something, but each advice provider is certain that they know the only “right” way. Myself Included.

Whatever way you go, good luck.


I've agree with NatersXJ6 on this. Especially given the size of your rig and available power. I would also say that it looks like you may have enough room under your hood for another battery which would save you some room in your cab. With my Jeep, I had the opposite problem (no room under the hood) and opted for a battery box in the back that I install before trips. I recharge the 2nd battery with a basic isolator found on Amazon.

As for the S-Pod, I find them too costly though their reputation for quality and customer service are excellent. There are other options that do the same thing for half the price but even these make the most sense for someone with a more difficult wiring problem. Your rig's age implies a simplicity in adding wiring and switches. I would take the opportunity to learn the basics of wiring. One, it's pretty easy and two, the knowledge will be very useful when something goes wrong.


I've done some light rewiring; I had to move a lot around under the hood because of things I've done already, and started to move things around. I cut out some added wiring not on any schematic that went nowhere (like an old jumper for a towing harness that was then cut out) and moved turn signals and the license plate light. Little things like that.

If I told you I could find lockers right now for it, and what type they were, I would know the answer to most of my questions. I can't even find an LSD for it; if I could I would simply do that. But no dice yet. It looks like I will spend next summer doing some wheeling and finding out how much I need them anyway, but the exhaust and electrical are the two upgrades for sure I want to tackle. I have a replacement dash for my broken one, so I have to pull the old one anyway; I think some of the vents are not connected to the HVAC anymore, and I have to check the heater core, too.

My needs for switches at this point would be:
-aux light/spot
-aux light/bar
-rear antenna light (elevated)
-perhaps compressor (still looking at the pros and cons of hard wiring vs. mounting
-on/off for extra power to mid/rear

If I hooked up the panel to deal with the above, and then was able to add a second battery in a portable box to deal with what I would need those times when I would, in fact, need it, that would be fine. Even if I simply get it ready for when I am prepared to use it, I'd like that.


Engineer In Residence
A larger alternator does not inherently put more load on an engine. A 100A alternator outputting 50A has approximately the same load (possibly less) as a 50A alternator outputting 50A. In general you should use the largest alternator that fits (barring any cost considerations). On some engines, a very large alternator can sometimes cause a stall if a large load is applied at idle. This is pretty unusual, and is usually related to a marginal fueling system (carburetor, very old fuel injection without feedback, etc).

Making your own switch panels (with or without relays) is not technically challenging. Purchase some contura switches, such as from this site.

For a robust and easily assembled system, use the recommended terminals and terminal housings. This makes durable fully assembled plugs for each switch. You can also use standard 1/4" spade terminals. Assemble into one of the switch panels for contura switches, and mount wherever. If desired you can use light gauge wiring for the switches, and place a relay near to your high current loads. This can reduce wire run lengths, and save on wire costs in some cases.


Over the years, from owners of Rockys near and far, they have reported that some alternators cause enough of a drain on the motor to be noticeable. It's been indifferent with some of the Toyota ones, but one of the people I read about in Australia used an LC alt (I can get which one if it matters, but the motor combo is not one sold in America so this one wasn't a choice for me) and it was a concern.

That having been said, space is a legit concern. I do not have power steering (I think that's on the same side as the alt, but I don't know for sure) and I just removed the A/C (that was opposite side of the alt) but there simply isn't a lot of space in there; it's a 1.6 4 cyl. I did not truthfully check, and measure alts, but in order to fit the Isuzu alt I used, which was plug and play, I had to go to the extreme end of the bracket, and I think I should actually get a new bracket: there's some squeal and I'm not sure it's far enough out.


Engineer In Residence
A larger alternator may have a higher inertia rotor. That will create a transient increase in load during RPM changes. Steady state operation load will be roughly the same though.

In some cases the higher output alternator does not have any more inertia. The field coil and rotor are the same size, instead the output windings are more numerous, heavier, or have more phases.

There is a fan on the alternator, but that is not likely to create a significant load difference between various alternator sizes.


For whatever it's worth, the proposed "run" from whatever panel I put in off of the battery to the light switches in the cab/on the dash will likely be less than four feet. I'll take some more pics after I sketch out what it is that I'm thinking of.

The "run" from the engine compartment to the rear where the fridge/ish would be is obviously longer. I don't know the way I'd run the wires yet, because I have no carpet in there so I don't want to do that. I don't know that I want to use the inside of the frame like the brake lines to run it back, and then pop up.

The PO (or, one of them, anyway) installed a much larger gas tank than stock: by math, it looks like an 18 gallon tank. To get access to the sending unit, someone cut a hole in the rear floor and made a flap to cover it using the floor steel they cut. You can see it here:

After I cleaned it and Monstalined it, this is the same patch (you can also see the old/current dash) here:

In short: I already have some access to a place to run something. In that final picture above, the Grade 8 bolts in the floor are for the bracket the folding seat latches to. Somewhere that far back, coming out of the floor somewhere, would be where I place a plug or wire for accessory usage. The bolts painted red (which was stupid of me to do, by the way) are the seat belt mounts for rear passengers...also giving you an idea where I want to run something.


luthj, the difference between that LC alt and the stock alt is like a plum to a Grapefruit. I agree with what you're saying, and understand, but until I dove into all this, I had no idea how small an alt could be. That 50 was bananas small.


Engineer In Residence
75A is plenty for charging a 100AH battery and running engine/lights etc. My estimates: When running a winch, you will see transients over 300A, with sustained bursts over 200A for rated load pulling (based on your vehicle weight and winch size). Only the largest of alternators can supply that current on their own. So you will be relying on the battery(s) to supply the remaining current above 75A (less at idle).

It looks like most of your runs are pretty short, which will make your wiring lighter and cheaper.

For switch panels, there are some nice pre-made marine panels. These usually have 3-8 toggle or similar style switches. Some will also have a dedicated thermal breaker next to each switched circuit.
Some options on Amazon.

Obviously check your current needs, as many are limited to 15A per circuit.


So, now you're getting into "the good stuff." I believe you completely, that the battery now comes into play.

Perhaps the million-dollar question (for me) is whether or not the alt, with a good "standard"/house battery can handle it, and for how long. Related to this, and the whole purpose of this post: specifically to hedge against an electrical flaw/weakness when winching, would a portable battery added to the system specifically when I plan on needing to winch/use a fridge work? Could I add the battery capacity when needed via a beefy cable connecting to some sort of isolator so that it will still charge but be available for use by the winch?


Engineer In Residence
A lead acid Aux can definitely assist with winching. A 200AH lead bank (about 150lbs) in deep cycle flavor should supply all the cranking and winching power you need. It is not likely to fit under your hood unless you can mount one battery on each side of the vehicle. Given your minimal deep cycling needs and irregular fridge usage, this does not make as much sense though.

Given the size of your vehicle, and wanting to control your weight, you may consider the biggest high quality dual purpose battery that will fit in your starting location. If you can fit a 100AH battery, you can even get something with decent deep cycling ability. These batteries can handle winching without much trouble, as they are routinely used to start big diesels with need 200A.

Given the short length of the vehicle, you could also mount the starting battery in the cab, or under the vehicle if there is room. This would give you more flexibility on sizing the battery. Appropriate cables would be needed.

If desired a mobile power box with 50-100AH (lead or lithium) battery could be built. Something like a goal zero, just actually a good value. This could be moved in-out of the vehicle as needed. A anderson powerpole connection would allow charging from the alternator. With correct sized wiring, a lead powerpack could also assist with winching needs.

Your alternators voltage will play a big role, I suggest measuring it at hot idle. Measure directly from the alt (case and B+ output stud), and also from your main fuse block. If significantly different, you need to address the voltage drops.

Will you have front winch only? Front and rear? Movable winch on receiver?
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I assume that 200aH bank you mean are the GC batts you posted about before?

I do have to measure the Alt for sure. I actually sent a message to the two Aussies that had the LC alt to see if they can say more. I am interested in seeing what I can do there. Not getting it now, as I just added the one. But with new extractors, fresh injectors, and the A/C delete, I have to think I can handle the increase.

The plan is a front winch only. I do not have a hitch on the front to do a portable mount and simply slide it back to forth as needed. THE ONLY WAY OUT IS FORWARD...AND THROUGH!
/Joe Pike reference


Engineer In Residence
I assume that 200aH bank you mean are the GC batts you posted about before?
That is one option. To run a winch, and start an engine in cold weather, you need a certain amount of cranking amps (or cold cranking amps). A 50-75AH starter type lead acid battery can do this. A flooded true deep cycle would need to be 150-200AH. A hybrid type flooded battery 100AH would be sufficient. The closer to a true starter battery you get, the poorer deep cycle performance/life you can expect.

Some AGMs can provide starter level cranking amps while still performing acceptably at deep cycling. These are expensive though, and need babied with regards to charge profiles to last long deep cycling.

For example a lifeline 125Ah group 31 battery can supply 650 CCA while still providing good deep cycle performance.
This is a 350$ battery though, and if you are deep cycling it, you need to charge to 14.4V until return amps drop below 0.5A, at least every third cycle. This can take 5+ hours. If you have the $$ or must have AGM/sealed, the Lifelines can be equalize/recovery charged, which can dramatically reduce capacity loss from deficit cycling (never reaching 100%). Most AGMs cannot tolerate this, and thus suffer from early sulfation. Not a big deal if you are not deep cycling. Note that extensive winching can draw down a battery, so a overnight top off with a good 120V charger may be called for after a trip.

Some folks just carry a lithium jumper pack, and consider their starting battery disposable (every other year or every year in some cases). In that case I would just put the largest marine/hybrid battery you can fit under the hood.

This may seem complicated, but its really just a sliding scale of cost per AH/cycle and weight needs. Lots of options, which can allow tailoring for your needs. The ideal is a system that meets your weight and space constraints, and allows for trouble free, and no stress usage in your application.
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I know I won't be driving it for 5 hours. So...that likely won't help, to get a good battery and then waste it by not taking care of it.

Like I said, I would like to have a good/great battery under the hood, and be able to supplement as needed, the times when I know I'll be going out for a weekend+.


Engineer In Residence
The 5 hour charge need is pretty common to lead acid batteries that are deep cycled. If you are only out for a few days, you can just plug in when you get home.

Sounds like you can go with a 75-100AH flooded marine/hybrid battery under the hood. A portable battery (or box if you desire), can be plugged in the back. Batteries that are different ages, or different types/sizes should not be connected in parallel (except when charging/driving). So you would need a isolation/charge relay that can handle your expected load. This would be pretty beefy if you are splitting winching loads between two batteries.