Diesel battery ?

[Fencer]

I have my first diesel truck. and as you with diesels know they have 2 batteries. I parked it friday, ran fine, yest about 4 pm the alarm is going off. I go out to check it, no one around, nothing seems wrong with the truck, go back in and forget about it.

Today, just now, 4:30 pm. I go to put something in the truck and find the battery(s) are dead. one is 5.3V the other is 4.8V.

The question(s) are if one dies, do both die? do you have to replace both at once? Can the other be recharged?

With the alarm going off (chevy factory) is that a signal of a short or is the alarm reacting to low voltage?

OEM AC Delco batteries 3 years old.

 

[DucatiSSsp]

Replace both batteries at the same time. What make, year truck? Lot's of good diesel truck web sites out there!

Bryce

Former owner of a 03 Ford F250 PSD

 

[Fencer]

04 Chevy 3500 6.6 turbo diesel LLY engine

 

[Wingman]

04 Chevy 3500 6.6 turbo diesel LLY engine

If it's still under warranty, try for the free replacement route. I got a new battery installed in my 97 Chevy PU one month before the original warranty ran out. Otherwise, I would charge each battery separately and test with a load tester before calling them toast. If one is bad, the other is usually not far behind. Definitely replace them as a pair if one is bad.

Might want to check for any drains on the battery also, assuming the charging system checks out good.

David

 

[Fencer]

Well, I guess the cost will be about the same as 2 batteries (time is a diff matter). I finally got it jumped, drove to the auto store and had them check me out. Both bats tested good, the alt, showed a bad diode. watching the volt meter in the cab, it was showing 13.5V with nothing on. I think I am a hair out of warranty. time to pull the paperwork to see if I sprang for the extended.