Sooo.
Batteries-
unfortunately new batteries these days and their components have significantly gone down in quality compared to 10-15 years ago. A six month old battery does not surprise me that all of a sudden displays problems. And like was mentioned earlier. Just cause a volt meter is reading “okay” does not indicate a cell or component inside the battery is failing.
-Why replacing batteries without technical explanation.
I will flip that back to you. Why would you remove the aux battery just cause someone on the internet said so?
And from personal experience. I had electrical gremlins with my last Jeep and played the entire gamut of battery mumbo jumbo. After all the bullshit and configurations. Guess what resolved everything? Replacing both batteries with new ones from the dealership. Even after replacing the main battery a few months prior. What your describing was exactly what I went through.
-30 years experience.
Not to discredit your experience or knowledge and I agree you are kinda on the right track. However your training and experience is based off of 50 year old technology. Why on earth would you experiment by removing electrical components on a 60,000+ dollar vehicle and not want to try just replacing the easiest and cheapest thing. A pair of batteries.
Also
Added benefit is if nothing changes you can come back and say that I’m wrong and feel good about yourself.
I'm not here to prove who's right and wrong and get satisfaction. I don't care who's right and wrong. I'll eat crow gladly all day long if I'm wrong and I'm just trying to fix a problem.
What I am understanding from your post is you are you saying that a 6 month old battery that load tested fine on a reputable auto shop's battery tester, not just my voltmeter could be bad?
I'm not saying you are wrong in the current battery quality control and bad batteries off the shelf. My sole issue is If a battery is bad, its bad. If I have a bad cell / battery it just doesn't come back to life on its own after one day of acting up. A battery is good or bad. No middle ground. Maybe that reasoning is wrong? So running from with no aux battery for months with no issues, and then replacing the main battery and running 6-7+ months with no problem leads me to think other factors are at play. Why would my DIC show a voltage of 10.4V and that battery show 12.7V at the terminals? Seems to something else at play?
In my wiring experience, if there is a wiring failure, it fails. Unless you have a chaffed wire that sometimes sees a short to ground during vibration or something,, it fails 100% time. Or a loose ground that can cuase the electrical intermittent fault. I've removed and re-torqued all grounds at the fender and frame rail. But its not a hardware problem like a battery or alternator. Yes, maybe I'm too old in my career to understand this.
The problem I have is the fact that this problem is intermittent. The truck still drives fine as of today, 3+ days later. That wants to me think that there is a glitch somewhere whether its a IBS sensor or something in the PCM or the Can bus connector / software issue that caued that malfunction.
Maybe i should follow your experience of changing both batteries with your gremlins. Sadly that's about another $400 bucks if I do the work myself and $800-900 if I have a shop do the aux replacement since the shop won't warranty my main battery from January that tested fine on the load test.
I'm by no means a battery engineer or a software engineer that knows exactly what this system requires for voltage to all the modules to run properly.
Yeah, I got rid of the aux battery based on many members personal experience's, but sure seems like there are a lot of owners to have removed the aux battery with no ill side affects after the fact.
Thanks for your input. Appreciate it.