ELECTRICAL PROBLEMS - 2017 Powerless truck

My 2017 TRD Taco is having some electrical problems resulting in an unresponsive truck, no power locks, no ignition nada.
Hopefully one of you here can help me chase it down.

ELECTRICAL MODS TO MY RIG:
By previous owner ⬇️
- Genesis Off-Road Dual Battery Kit with Smart Isolator
- Dual

$380 Odyssey 34-PC1500T Automotive and LTV Battery

Odyssey 34-PC1500T AGM LTV Battery
- Victron Smart Solar MPPT 100/20 Solar Charge Controller 100V 20A with Bluetooth
- Victron Smart Battery Sense Temperature / Voltage Sensor
- Blue Sea Systems Auxiliary Fuse Box Integrated Under the Hood
- Roof Rack Electrical Prep 2x 8 Awg. Run from Aux Fuse Block
- Bed Electrical Prep 2x8 Awg. Run from Aux Fuse Block
- Built in Aux Switch Controls 10 Amp Circuit Brokered x6 Marine Grade
- 2 Roof Rack Mounted 100-Watt 12 Volt Monocrystalline Solar Panels 10 Awg. Wired
- Pop Lock Power Locking Tail Gate Mod (Passenger Door Sync)

Mods done myself ⬇️
- MPC remote start kit for OEM key fob (plug-&-play, no alterations to factory wiring harness.
- individual wire harness temporarily run for auxiliary fog lights.
- winch wired directly off pimary battery (as instructed by installation instructions)
- more planned, none started.

CONTEXT:
My truck sits waiting while I’m out of town, often for months on end.
I leave the tank mostly empty and put fuel stabilizer but have not given the same care to the electrical by disconnecting the battery terminals. Instead utilizing the override button on the genesis smart isolator between the main and Aux batteries to dump power into the main and start the truck should I find it dead (twice this has happened when returning home)

INSTANCE OF FAILURE:
Return home yesterday from 3+ months away.
Not enough juice in the main battery to turn the engine over, but enough to unlock the car and power some of the main console (door ajar graphic)
Do afore mentioned process, and drive away. Day passes no issue.

Today the center console starts shutting off temporarily and coming back on a few seconds later, with continued frequency.

come out from the grocery store towards EOD and key fob doesn’t unlock the car.
Get in no power. Pop hood see that there’s some amount of juice in the battery’s, and that one of the auxiliary items in the truck is receiving power.
Get back in, push to start. Starts.
Drive home.
En route, Notice same stero issue, and now that it’s dusk, have turned on the headlights and noticing other electrical “short outs” (for lack of a better descriptor) in the dash board (check engine lights, etc.) going out and coming back on with the center stereo. But no effect on the mechanical operation of the vehicle.

park truck, lock with key fob. leave it for some hours.

Step back out, same condition as before, no juice to any of the vehicles primary systems.
Meter batteries, both near where they should be (12-12.7v)
, start poking around the fuse boxes under the hood, no smoking gun.
Get in the seat, reach low for the left hand driver side fuse are. Get a lite shock (could have been 12v ‍♂️)

lights pop on, start engine. Runs fine no issue for 10min.

turn it off. Dead in the water again.

Went inside to read forums and seek assistance

IN “CONCLUSION”
I suspect maybe
A 12v short to ground somewhere. B a fuse or relay that was weak and has now gone?
Or C something outside my limited knowledge that one of you brilliant taco hive-minders can hep me figure out in the next 48 hours when I really need my rig to work.

thanks for reading my short story

any help would be greatly appreciated

 

"Get in the seat, reach low for the left hand driver side fuse are. Get a lite shock (could have been 12v ‍♂️)
lights pop on, start engine. Runs fine no issue for 10min.
turn it off. Dead in the water again."

^^^^^^^
Get a good bright light and start looking where you got the shock, it sounds like there is a loose connection there.

 

You cant let your truck sit 3 months and expect it to start. Every mod is an potential problem. I would disconnect as much as possible and charge the battery. How old is the battery ? A bad battery can read 12 V and then fall off with a load.

 

My batteries usually read around 13.4-13.6 with the engine off...

 

You will have to find the loose connections for sure,,, sounds like a hornet's nest of wiring though
To add: if you are leaving any battery for months at a time, it should be on a battery tender of sorts. Also, you’re starting nearly dead, and not fully recharging, is adding to the stress, I doubt you are fully recharging nearly dead batteries on errand trips. Think of your alternator’s job as topping off the battery from the charge you used to start,,,, not an actual recharger to bring back from the dead.

 

repeated driving to charge dead batts is beating on your alternator, shortening its life (brushes mostly but also what they ride on).

 

How old is your battery?

 

UPDATE:
I found there was light corrosion around the negative pole on my main battery, and a good scrub seems to have resolved the issue for now.

@RustyGreen did that for awhile and found no smoking gun. still suspicious where the slight shock could have originated from

@BOBSTOY 53 and yet with the auxiliary battery on a solar charge, I mange to turn the engine over just fine. Though you are correct, I should disconnect the batteries and put it on a trickle when I'm away. battery is 3-5 years old

@Chew the wiring is clean, and I was unable to find a loose connection, not for want of trying. you are correct in that greater care needs to be taken of my batteries when away. I do typically leave her running after I initially start the truck for a half hour or more before I get rolling on my "errands" Limitations of alternator noted Not a voodoo which doctor.
. thanks for that.

good knowledge. thanks.

 

Rather than a "trickle charger" you want an "battery maintainer".

There is a fair amount of tech packed in these little units, not really a place for a Harbor Freight unit.

Two units to consider are NOCO Genius 1 or a Deltran Battery Tender.
Both brands are tech leaders and well established with good reputations.
Either model is easily available at online, your local auto parts store or The Mart for around $30.

The NOCO unit has more functions, the Deltran is slightly easier to use, I have several of both and they have given good service.


https://no.co/products/charging/genius

https://www.batterytender.com/battery-chargers