I have at least 1 maybe 2 batteries that need replacing. Is it best just to do all 4? Which of the batteries start truck? Is there anything to reset afterwards since there will be a temporary power shortage?

 

When I had my own truck, I would replace the ones that were going bad or getting weak, rather than replacing all four. I don't believe there are any trucks out anymore that have split-service on the batteries. But,even with that, if you have 4 batteries, and the truck is only using 2 when it is running, it will still be using all 4 when cranking.

And, as to what to reset... The clocks. Any clocks you have inside that are powered by the batteries will either reset themselves to 12:00 (digital), or stop running while the power is off. Beyond that, I have never heard of anything needing to be reset in the ECM or anything like that.

 

How old is those batteries? Normally, I'd recommend all 4, it's safer that way....
And no, you don't need a "reset" anything, but the clock....

 

The batteries are all the same but, one of the batteries is a 2006. Not sure about the others because the stickers are gone. Gonna take them to Autozone this weekend and have them tested. The batteries are Interstate, btw.

 

the batteries can test good today & next month go out. I always replace all my 4 at the same time. though I'M one of those guy's who replace both wiper blades at same time also. when I park my truck I want to have as much peace of mind as possible knowing the likelyhood that my truck will start.

 

So it's about 3 years old, and i get it's not you, who put it in service? I'd go with all 4....

 

If you don't replace them all it doesn't take long for all four to only be as strong as the weakest one you left in. Your call.

 

Yep, road calls usually start at around $100.00.

I change all 4 after they make it thru 3 winters, I don't care how they check out, 3 winters.......... they are GONE

 

I think it's unanimous

 

The problem is if you change only 3, and the fourth one internally shorts a week later guess what happens? It completely drains the 3 new batteries.

Completely draining batteries absolutely kills them. Even brand new ones.