03 6.0 Drivers side battery won't charge

[Regis1320]

Hey guys, I've been doing some research and i'm not finding too much here. Here's what i have, an 03 6.0 f250. Since It's been getting colder lately it's been harder to start, and if I let it sit more than a day it won't start. It won't jump off the drivers side battery. I had the batteries tested at interstate and they were just discharged. The tech checked all the cells and they were ok. With the truck running, voltage is at 14.1 on the passenger battery, and 12.9 drivers side battery. We swapped the drivers side battery with a known good battery and had the same results. The alternator was replaced earlier this year. Any tips guys? I found a thread about 03's having a ground near the crank pulley that goes bad so i'll start checking there for now and see what i find.

[Regis1320]

I removed the drivers side battery ground off of the frame rail and cleaned it. It looked fine and I reinstalled it. I also removed and cleaned the engine ground on the pass side of the crank pulley, that looked fine as well. I'll see how it starts tomorrow morning and put a meter on both of the batteries. I'm sure it's going to be something else, it's never something easy.

[Regis1320]

Still having this issue. Just had to jump it cause of the cold. I believe I need to check the power wire that connects the passenger side battery to the drivers side battery that runs along the radiator. I pulled up the diagram on alldata and I don't see what else it could be. All the fusible links go to the passenger side battery first.

[Regis1320]

I changed the alternator out with a friends brand new one and same thing. Nothing changed. I checked his truck and both his batteries are at 14.x while running.

[capcalvin]

I would guess bad battery or poor connection somewhere. Did you try swaping the batteries? (Put drivers side on the passenger side and put passenger side on the drivers side?) While you have them disconnected, charge each battery by its self to see if they take a full charge. My guess is battery becouse you are saying that it may be weather related.