well hers the thing i have a 99 ford f-350 7.3L diesel last saturday was running perfectly fine all day came to nite time and it wouldent start so i needed a jump got it going made it home okay. charged the batteries during the nite the following day turned on like nothing drove it fine all day till the nite time it needed a jump again . so i bought new batteries for it the following week started up fine my mom took it and had no problems..Well the day after that i took it to work and noticed the batterie gauge was going low , after work it wouldent start n e more so i needed a jump again .. as i was driving home it shut off completely on me while driving .. .. I NEED HELP KNOWING WUT THE PROBLEM MAY BE I CHANGED THE SILONOID AND NOTHING I HAVE TO CHARGE THE BATTERIE FOR 10 MIN AND IT WILL START RIGHT UP AFTER THAT ALL THE GUAGES WILL GO LOW AND IT WILL TURN OFF WUT CAN B THE PROBLEM??

 

sounds like the alternator is not charging correctly.

 

THATS wut i thought but i heard if u disconect a cable from the battery while its on and the alterantor is bad it should turn off after disconecting but it stayd on. theyve told me its cuz off my sound system but dought it had it since the truck was bought they have told me it might b a short or the computer is reading wrong

 

Welcome to FTE. Don't take this the wrong way, but it sure makes life easier on us old folks if you use punctuation and capitalize letters at the beginning of a sentence.

Have you cleaned and tightened your battery cable connections? Remember each cable has 2 ends. Clean them both. Does the battery light come on in the dash? If so that's usually a sign of a bad alternator. Many parts stores will test the alternator for you for free while it's still in the vehicle.

Since you've got a sound system, the easy way to rule that out is to simply pull the fuse(s) powering your sound system each time you park it. If that doesn't fix the problem, then it's not the sound system. If it does, something has happened and you've got a current draw coming from the system. I'd also ask your mother if she used the stereo or if she turned it off when she parked, or see if there's anything else she might have done differently than what you typically do.

 

Yes, i have checked my battery cables and they are clean and tight , as for the battery light its been on for i want to say more than three years .. but had no problem then . so now wut the truck does when i turn the ignition key to the run on position before starting the guages come up wich are the battery and the temp then they go down like if there where a short somewhere. I dont think the system has to do with it its been having one since 2000. I have also uhooked the main power to the system but i get the same results

 

Not sure the "unplug the battery to see if it stays running" is a good way to check things on a diesel either. Once running, a diesel does not have an ignition system drawing amperage. Just the fuel pump. So it would stay running at idle, even at very low battery voltage, I would think. Clean all your battery/ground connections, have local parts store load check your alternator.

 

In the future you probably should address warning light indicators quicker than 3 years. That battery light indicates you have a voltage problem. The free alternator check is a good place to start. Make sure your sound system is hooked up for the test. What size batteries did you put in it? Maybe the batteries don't have a large enough rating? You did replace both at the same time, right?

And just because the sound system has been on there since 2000 doesn't mean something has broken or shorted out suddenly. How many other 11 year old pieces of electronics do you own?

 

Moved to the 1999 - 2003 7.3L Power Stroke Diesel forum.