I went to a shop today to get my batteries tested (factory originals). I thought I'd read on here that they need to be disconnected but he said no, checked them both while connected and told me they're fine. Did I get an accurate test? I'm going to be driving alone into some isolated areas in the next few days and need to know the truck is going to start.

 

With the truck off, first thing in the morning after the truck has been sitting all night, put a multimeter on the terminals. 12+v, you're golden. No need to unhook the terminals.

Normal life span is 4-5 years for stock batteries. Longer most times.

 

I just disconnected my battery on 2006/3500. I cleaned terminals because of the dirty negative acid build up. Driving down road then cruise control, engine light,red temp guage lit up. Started down shifting hard after traveling 3000rpm. Stereo stopped working also. 66000 miles, no mods, stock diesel truck. Now she sitting at dealer. I havent had any problems since new.

 

Good point. Bad battery/ground connections can lead to a lot of problems in our trucks.

 

So you're all saying don't touch it

 

Spoke with service advisor at Lone Star Dealer on 35/Somerset. Batteries were replaced and throttle valve actuator is the problem. Truck has been there for a week. Parts not in stock. Dealer item.

 

To properly load test or test with those new fangled digital load tester deals the batteries must be separated from each other. It's as simple as disconnecting one ground cable.