2023 Freightliner Issue - PLEASE HELP

So, just a quick update.....


As I'd said before, I had one battery replaced and woke up with that BRAND NEW battery boiling this morning. After talking with the mechanic, I decided to have all 4 batteries replaced. They were 750 CCA and now 950 CCA.

Problem is still here.... I don't want to jinx myself, but with all 4 new batteries, the voltage fluctuates the same and drops to 9 when engine is off. I kinda think I'll wake to another boiling battery. I now have an occasional beep coming from my dash too, a single and quiet beep. Seems to happen every 2 minutes.

The mechanic verified the alternator voltage after these new batteries, he followed the power and ground cables from the battery box area, and he even called an out of state freightliner to ask for advice. No chafed or exposed wires, alt voltage great, and freightliner had no clue at all on what the issue would be.

He said if problems continue, he will run a continuity test tomorrow? He has some kind of claw type tool that you run up and down a wire to find issues.

Now I'm wondering what you guys think. Where does the dash read voltage from? Could that be faulty? Could both the old battery and brand new one that boiled over night have been a coincidence? I desperately need help.....

I was at Velocity out of Lexington Ky a week ago for electrical problems. MSF issues were to blame. I took it there twice and they worked on the MSF both times. First time there were missing switches I believe he said, and second time it was unplugged. Surely that wouldn't be my issue right? Especially since a great shop with nothing but great reviews looked at it not once, but twice. He also found a short in the bunk wiring for the light but fixed that too, and I haven't had the issues I'd taken it in for since. But these new voltage problems started after 4200 miles? I need some advice here.

 

Think that's my only option..... Been parked for 4 days. Stopped for a 34 and #### hit the fan. Really not looking forward to the waiting time though..... Only place near me is north of Denver, 130 miles away.....

 

Alright, so you were actually on the right trail! Took it to a AIM lease shop since they are the company I went through for my truck. They replaced all 4 brand new batteries AGAIN, put a brand new alternator, and correctly tested everything. So, after 9 brand new batteries, a new alternator, and almost a week of sitting, they found out is was the whole battery module that's got the 5 amp Remote Sense fuse. It was getting red hot somewhere he said, causing the voltage on the dash to be incorrect. Alt was overcharging batteries but the dash was showing way lower voltage.

Glad I now have this figured out, and documented for other drivers.

If anyone is ever experiencing boiling batteries, but the dash doesn't show overcharging, it could very well be the battery module. Mine was on the passenger side, under the hood on the fire wall. Red light was solid, indicating properly working, but it wasn't actually working.