Man, have I got a problem(s).

I have a 2020 Sport garage queen. 3,800 miles and has never seen rain or snow.

A few months back I installed a Magnuson supercharger. I also installed boost & AFR gauges from Speedhut.

A month or so after completion the battery went dead, and I mean DEAD. It was so dead I thought I had left off the battery cable but since the battery is so new it charged up okay without any apparent damage. So, obviously I've got a parasitic draw from somewhere.
I found a Toyota bulletin somewhere online explaining how to properly check the draw and it showed 75 milliamps. Way over spec.
I've only made (3) connections to the electrical system: 1) supercharger coolant pump, 2) gauge power, & 3) gauge lighting. I unplugged all three connections and the battery draw stayed the same. That's problem #1.

Problem #2:
Since this isn't driven everyday I've been messing with it for several weeks when I had the time. I've checked the battery draw many time so I've had the negative cable off the battery more times than I can count. I've even been leaving it off when out of town to save the battery. I didn't get consistent reading until I used the Toyota bulletin which outlines the proper steps and order.
Yesterday I got a consistent 75 milliamps using the info from Toyota. THEN this morning the truck wouldn't start. It rolls over fine but will not fire.

What in the world did I do?

One caveat: per all the instructions I've ever read, I locked the hood latch using a screw driver before testing. THEN when finished I forgot to open the latch before trying to close the hood. Thank goodness I didn't try to SLAM the hood but it still didn't like it. Could this have tripped something in the security system preventing it from firing? I've let the truck sit with and without the battery cable connected hoping it would reset SOMETHING but so far, no luck.

Another caveat on the parasitic draw: the only other electrical mod I've made was adding the 2WD Low Range wiring harness but that was last year.

I sure would appreciate any help with this.
Thanks.

 

Keeping a battery maintainer on it would be the first step I would do if not driving all the time

 

Yeah a battery tender on it

 

If you have removed the 3 modifications that you have made and are still finding the draw to be excessive, then start pulling fuses one by one and check until you find the circuit that is causing the draw.

On the flip side, newer vehicles have more and more parasitic drag on the electrical system.... my wife's Impreza doesn't get driven much and has had 4 batteries in it's 11 years. My Tacoma is driven daily and still has the factory battery after 5 years. If you are parked a lot, then a quality battery maintainer is a must. Something that is smart charging. I use NOCO on my RV batteries. I have had some maintainers in the past that killed batteries, boiled them dry. The NOCO units have extended the the service life of my RV batteries by double or more...

 

I'd pull the 2 wheel drive low mode to just to rule it out. When you're performing the draw test you're locking the doors and waiting a while before performing the test right? And also are you 100% sure you didn't break the connection between the battery and the negative cable (meter should be the bridge)? If you did this will wake the systems up again giving you a false reading.

If all of that checks out start pulling fuses until the draw goes away. I've had to chase a draw down before and it's annoying. For a long time I just left it and kept the car on a charger as it would die after 4 or 5 days.

This tool helped me when I was chasing it down. It allowed you to have the negative terminal already disconnected and let the car shutdown. All you had to do was flip a switch to change over to the meter. Eliminating the chance of you breaking the connection and having to start the test over.

https://www.lislecorp.com/specialty-tools/parasitic-drain-tester

 

Yes, I tripped the hood latch, rolled the drivers window down, locked the doors, cycled the ignition, and waited for the truck to go to sleep. And I'm very confident I didn't break the circuit while removing the battery cable.
My next step was to start pulling fuses but now the parasitic draw is less concerning than the "not firing" issue. This has me stumped and more than a little freaked.

 

Sorry but I haven’t read past the first two sentences and can’t help but think of this analogy. A supercharger on a truck that’s never driven is like a priest who purchases condoms. Why?

 

Might you have anything you leave in the truck, like a jump pack, that is continuously plugged into the USB charger? If so, that will be your culprit.

 

Hilarious !

 

Yeah, I guess I need to wait until the grown-ups get home from work.

 

How long are you waiting after ignition off to check for draw?

 

So he can "accidently" drop one on the floor in front of his friend, so they think hes getting some.

 

that fuse idea is probably the most promising, apart from that plug in the battery tender and live with it. Also, did you do the mods or was it a shop, if it was a shop maybe give them call.

 

UPDATE:

It dawned on me to check the fuel pump fuse on the slim chance it was blown and causing the issue with starting. When I removed the engine bay fuse cover I noticed I forgot to replace the supercharger 10 amp add-a-fuse after my last battery draw test. Once I replaced that she fired right up! I assumed the fuse was just for the Magnuson coolant pump but apparently there's more to it than that. PHEW! I should have known it would be something stupid.

Now I can go back to finding the parasitic draw.

 

Hell! I got them hanging from my mirror and all the knobs on the dash!

 

I've been waiting a least 45 minutes.

 

For reference, after sitting several days my stock 2020 OR is 9.5mA, brief and occasionally spikes to 11mA.

 

Sorry, ‘twas low hanging fruit, best of luck OP!

 

Correct me if I am wrong but my understanding is every time a battery is completely depleted, it suffers irreversible damage. So a battery can only completely “die” and get recharged again for a limited number of times before it dies for real and needs to be replaced.