Battery Relo - Electrical amp/current question (with diagram)

**Not LTX specific but it is my 94 TA**
*Warning: I'm also an idiot IT guy, so be nice*

There are countless threads on the Internet for battery relocations in a 4th gen. I get it, I looked at dozens. My car is close to running and I can begin to taste it, but the wind was taken from my sails last night when I tried to get it to turn over and my brand new (not reman) just went click, click, click. I turned the engine (5.3 - I know it's not an LTX) by hand and it moved. Had some water in 2 cylinders unfortunately from sitting outdoors but broke free once the plugs were out. No water in the oil so it must have been sitting on top of the piston. Despite the fuel system not being installed yet, I wanted to turn the engine over with the starter.

The car has a battery relocation kit from Summit. Used, but works and definitely worked when the LT1 was in the car. Started the car no problem. Attached to the battery positive terminal is a circuit breaker (200A). I don't remember the exact size cable that runs to the front of the car, but it is huge, like the size of a quarter or so. 1\0 gauge maybe? I don't remember offhand, but it doesn't get hot when in use or anything. The battery grounds to the body. Again, never an issue with this with the LT1. Since the LS swap, I did some rewiring, including a new harness from BP Automotive. I also rewired some shop handywork. The starter, alternator, and another junction box for the forward lamp harness all USED to connect to a stud in the engine bay. I replaced this with a fused junction box.

The battery is on the older side now and is an Odyssey PC1200, mounted in the DRIVER side rear compartment in a Taylor box. It has been sitting dormant for a LONG time. It charges no problem up to 12V but voltage drops to about 9 or 10V when cranking. The battery was on a trickle charger all weekend and said fully charged prior to my test. The breaker is 200 amps and the each terminal on the box under the hood is 80 amps each. See my attachment for a better explanation.

The starter is brand new. I swapped in an older, but working, truck starter and still clicks. A friend of mine gave the solenoid some massaging while cranking and nothing. That same friend is convinced the battery is junk. Tried jumping the starter with a screwdriver and a spare battery but that one was too weak.

I don't have a load tester and probably won't be able to do much troubleshooting for a few days, so now I'm reading and theorizing lol. Is the breaker and 80 amp fuse going to the starter hindering the starter from working properly? I'm currently shopping for a larger tray or battery box and a battery with a higher CCA rating, but I want to see if what I'm thinking even makes sense. The Odyssey has goofy posts and is tiny so I just can't throw in a good battery from my truck or something. Jumping the car off the battery would also prove to be difficult due to the car's location on my lift in the shop.

Attachment 39778

I would run the main line from 200amp breaker straight to starter lug, then feed the fuse box off the starter.

I'm thinking battery.

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^^^ I'd have to agree with both SNM and B.
80 amps isn't enough to operate a starter motor. The full battery current needs to be applied to it.
AGM batteries are sometimes hard to get to a full charge after sitting.
I read about a trick to get them to fully charge here;
https://www.hotrod.com/articles/hrdp...a-agm-battery/
Also I wanted to mention that I have had multiple bad experiences with the type of circuit breaker you are using. The ones I had go bad(two) were on my boat electrical system.
I payed premium dollars for them when I re-wired my boat and they apparently get corroded internally. You may try jumping it out with a battery cable to make sure it's good.
FWIW I laid the boat up awhile back and have been ignoring it. When I get it back running again the breaker will be replaced with a fuse. In my case its just a main breaker for the electrical system in the boat. The battery feed to the starter motor is un-fused. Also FWIW the ignition circuit to operate the starter is also un-fused. They are the only circuits allowed to be operated un-fused by current standards.

Crap, I forgot to mention my original thoughts regarding the negative side of the battery feed. I don't know what you have, but it needs to be just as big as the positive feed. Big wire feed to the frame and a big wire from frame to engine block. Could be your connection has gotten corroded where it attaches to the frame on one or both ends. I had a motorhome starter issue one time that was intermittent. Had what "appeared" to be perfect frame to engine block cable. Then when I took it apart it was rusty as hell in the connection. Cleaned it up then all was good.
Nolan

Thanks everyone for the feedback! Regarding the wires from the battery, ground is just as thick and goes to a good ground stud. The engine has two smaller gauge wires grounding it. One on the passenger side head and one behind the starter. This one was a tad loose during the troubleshooting phase and was torqued down. All wires are pretty new-ish, the car has like 2 or so miles on it since 2010. It moved briefly under it's own power when it was LT1 powered in 2016ish.

I read the link you posted, @JOATMON regarding AGM battery charging. It got me thinking. I have a NOCO Genius 10 charger for my C6Z. It has a lot of cool options including charging specific for lead, AGM, and lithium batteries. It also has a battery repair mode. I put it in repair mode late last night and appears to be finished, now. I will likely take the battery back down the the T/A tonight just to see what happens. I wanted to give it a try before buying more crap for this money pit.

what snm said and your battery is probably toast.

Update: Battery is toast. The AGM charging feature and repair mode on the NOCO charger didn't bring this battery back to life. I put my spare Corvette battery on the charger overnight and slapped some marine terminals on it (the terminals with a stud/wing nut on them) and connected the wires. The starter turned the motor over without hesitation. Then popped the 80 amp fuse, which was expected. I added two 80's to that connection in the fuse box (this was just for testing) and it worked great. Tried some starter fluid but I don't think it's getting spark but ran out of time. I need to check out the tune and finish the fuel system. Also, I am waiting on Amazon for some proper fuses.

That circuit breaker is also rated at 250 amps. My mistake.

Thanks all for the suggestions!