Electrical gremlins

Hi folks.

I’ve had my 2011 5.7L for two and a half years, and until today I’ve managed to diagnose everything that’s gone wrong with it just by reading existing posts. Today though, I’m stumped, and I wondered if anyone had an idea where to start in diagnosing what’s going on.

The first glitch was in the outside lane of I5. Flashed my lights at a moron who tried to undertake me and shoot a non-existent gap before a big rig, forcing me to brake, and for a half-second everything electrical shut off. Lights went out and came back on, stereo rebooted.

Drove another hundred miles or so without incident before needing to refuel, but after my gas stop things got worse. The dash would light up on a half turn of the key, but then when trying to start the truck it would turn over once and everything electrical would go dead. Disconnecting and reconnecting the battery reset it, but it did it again on attempt 2. Fortunately on attempt 3 it started, and I got it home without any issues while driving, but tried to start it this morning and it’s done the same thing.

As stated, I’m stumped. The truck was in the snow all weekend but it’s lived in the mountains for entire winters without issue. The problems didn’t start until a good 5hrs into the drive back either, well into central California.

Any and all ideas greatly appreciated, and thanks too for all the issues everyone here has already helped me solve by helping others.

 

Have you load checked your battery?

 

Yeah I would get the battery tested, cars can act super weird when the battery is going bad; when was the last time it was changed?

 

I think it’s been about a year, just over or under. Hunting for the Costco receipt right now Thanks, I’ll start with that and update in a bit.

 

May as well check for rodent damage too

 

there should be a small sticker on the battery like 4/24 which would be the month and date

 

Battery was installed Feb24.
Just got it checked at Autozone… bit confused as to how it can be at 100% but apparently the charging system is bad?

 

On that it says voltage regulation so alternator could be jumping around maybe? Put a multimeter on your battery terminals while the truck is running, do the numbers stay steady? Do they jump around? What’s it reading

 

Thanks. I’ll try to dig out my multimeter when I get home and get some numbers.

 

Hey folks

So… yep, alternator was the issue… however I got it rebuilt today and I have a follow-up question for you all. Driving home from the mechanic I noticed a squeak, almost a flutter at idle but riding to a screech when I accelerate. Noise tone is tied to rpm, and truck was purring before I dropped it off. Guessing it’s something to do with the belt or the rebuilt alternator. Any thoughts? Ideally I’d like to avoid the drive back to the mechanic’s tomorrow as they’re 40 miles away…

Thanks in advance for any and all assistance.