Electrical problems are always a pain.

Pardon my ignorance as I have not posted on this website yet and don't know if you all have a special place you post your troubleshooting problems at. I have a 2004 6.0 F-250 with 174,000 miles, and not a lick of electricity. I can get a jump start after sitting with jumper cables for about 15 minutes, drive around, turn off the truck and crank it back up on its own power, but once it sits for about an hour and a half it don't have enough power to start itself in the batteries. The light is dim, and if you let it sit overnight, there is NO power at all, no lights come on, door locks don't work, etc.

At first, I would think this is a problem with the batteries. But both batteries going at the exact same time? Highly improbable in my opinion. And even if it were two bad batteries, I would still get some kind of power to at least make the dome light flicker I would think! This makes me think it is an electrical problem, so yesterday I went off to the local auto store and grabbed a multimeter to try and troubleshoot it...when I got back, I suddenly realized I had no idea what the heck I was doing. The voltage between the terminals (having been jumped recently) was 11.75V on both batteries, that's all i know. I also know that this constant jumping them off and letting them die is bad for them and will ruin them if they are still good. I have no idea what to do, is there a way to check a wire to see if the system is indeed pulling power before I go out and buy new batteries unnecessarily?

Thanks,
A. Kyle Altmix

 

Welcome to FTE.

I have a gasser, but from what I understand, if one of the batteries in the diesel is weak, it will drag the other one down with it. Most folks here seem to replace them in pairs.

Is there a parts store that has free battery testing? Batteries are best tested under load, as they can have a "surface charge" that makes it appear as though they are good, until you try to use 'em. The testers at the parts store by me have a way of loading the battery. It takes a few minutes, but it will find a weak or dying battery much better than a voltmeter.

Just so you can find your way around, there is a separate forum here at FTE for 6.0 issues. If you get into EGR deletes and custom tunes, you will find the right folks in that forum to help you out. But your battery question is the kind that can go either here or there.

 

Your voltage is certainly too low. Several possibilities. You did not mention the age or condition of the batteries, but have them checked as suggested above. Since you are learning do the simply stuff that is important first. If the batteries test good, you might want to start by taking a close look at the connections to your batteries. You can have the best charging system in the world, but without good cables and connections, your batteries will become starved quickly. Just do the obvious first to get started, before you try to take on the entire system.

Congrats on getting meter. Once you learn how to use it, I think you will find the uses for it increase rapidly.

Steve

 

Welcome to FTE, I think you'll find this site very useful and full of great information. I too suspect your batteries are bad, but you won't know for sure until you have them tested. One thing however, before you take them in to get them tested you need to charge them up as much as you can. They can't do a load test on a dead battery.

 

Funny story lol...

I got a jump from a buddy and decided to drive it up the interstate for 15 miles to get a good charge from the alternator, and then take it to Autozone to get the batteries checked...halfway down the road there was a smell of sulfur that just got worse and worse. When I got to autozone, as I suspected, one of the batteries was swollen and hissing out acid. Needless to say, I got two new batteries and that fixed the problem straightaway.

I never knew that one dead battery drew power from the other good one! Also, thanks for the advice and the welcome to the page!

-Kyle

 

Sound good, however I'm thinking it might not also be a bad idea to check the output of your alternator to make sure it's charging properly. You could either check the voltage on the battery terminals with the engine running, or pull your alternator and have it tested just to make sure it's not over or under charging to make sure that didn't cause your battery problems in the first place. Also, make sure you wash the truck out under the hood where the acid was spraying out to wash the acid off so it doesn't start eating through other parts.