Hello all,
I have an 03 x, my 6.0L has the dual batts. and a single alt,.

went to the store for wife, came out of store and truck wouldn't start .
I ended up calling my brother and after taping on the starter lightly with no luck, we decided to try jumping it with his truck and it did start up.

After getting home and shutting it down I was back to the same thing.
This time I hooked my truck up to a batt, charger and got it running again.
I then took my fluke multi meter and attached it to first the drivers side batt, and then the pass, side.
The meter was reading 12.07 on both sides until I would rev the motor then it would climb to 12.41 or higher depending on how high I would rev it. Then drop back down to the 12.07 or maybe a bit higher 12.11 or so.

Now Im not sure how many volts the alt should be putting out, but that seems a bit low to me. Or is it just that the batt, are not holding a good enough charge. This is the first dual system for me. But it still seems that I should be able to apply the same logic as a single batt, system. But maybe Im wrong and just looking at this from the angle.

I hope that someone can enlighten me.
Or tell me that Im dumber than a box of rocks. Even though I have already checked the turn signal fluid, and it seem to be fine and not low at all.


Thanks for your time
Jeff

 

The dual battery system should be the same as a single battery.

Usually with the truck running the battery should read 13.5 to 14 volts. This shows the alternator is charging the batteries.

My guess is the alternator being the problem, But first I would make sure all connections are clean before replacing anything..

 

X 03 Jeff,

Drive to your local auto parts and let them load test each battery. That is an easy test and will give you a place to start checking.

There is one difference with a dual battery system, and that is if one battery is bad, you need to replace both batteries at the same time. If you replace just one battery the older battery will quickly ruin the new battery and you will have to replace both the old and new battery in short order.

Hope this helps

 

The constant voltage thru the system on your volt meter should be 12+ and when the Alt kicks in, to charge the system, it should show a 14+ reading. I have suggested before that a Volt meter is a necessity on these trucks.

Installed one here as A piller was full . . .(c gallery Tech folder)

 

I agree with the suggestion to take it to your favorite battery sales place and have them load test it. If your battery (s) is/are bad, it can make your alternator look bad...very heavy load. Make your decision what to replace AFTER the test. I believe from what you told us that it's the batteries. Replace both.

 

Thanks all,

I do think that a built in meter is a great idea for these trucks. This could save batteries and headaches among other things for all of us.

I did go with the alt, it was not to difficult at all to take off.

I took it to the parts store and you could hear the bearings where not in good shape and the brushes or something must have also been bad because it was not charging. $140.00 dollars later and about 15 minutes the truck was charging around 13.50 to 14.00.

I drove the truck around for awhile to charge back up the battery's and they seem to be holding around 12.30 to 12.50 when not running.

The only thing that concerns me now is, did I do any damage to the batteries ?

The light indicators that are on them now look green around the edges and a reddish color towards the middle. I hope there ok because another 2 or 300 dollars for new batts, does not sound to appealing. I probably should run on down to the parts store and have them load tested so I don’t end up stuck again. I just hope that they test good.

Thanks for your time

Jeff

 

dont go by the hydrometer eye. if this is the first time your batteries have been dead, then yes you have damaged them but only to a small degree. a brand new battery if drained dead will lose 20 or 30 percent of its life and 10 percent each occurence there after. get them load tested and if they pass then you may be ok but they may not last through the summer because extreme heat and cold really shows a battery's weakness. also remember that anytime you check a diesel charging system you need to maintain the meter reading for a few minutes due to the glow plug system. the charging system is pcm controlled on diesels to protect the glow plug system. so if the engine is started depending on the oil temp the alternater might not start charging for up to 2 minutes after the engine is running, and then it slowly comes up due to the drain that was on the batteries.

 

You know, you are right (Duh u r a tech). I notice this when I put the Volt meter in, for a while it stayed at 12+ and then jumped to 14+ after a few minutes. Didn't know why until now. Thanks for the insight, what a reputation you must be developing!

 

your welcome. i do what i can to know what i can. without knowledge i would just be working on chevies. lol. seriously, i love what i do and my thirst for how stuff works never dies, plus it makes me better at what i do.