My battery light was coming on while running and I checked the volts at the battery. With the light on, it was charging just under 14v DC, at 13.98v DC. I just changed my alternator today and immediately upon starting my truck, that damn light was on again. I checked the voltage again, it was 14v DC and holding strong and yet the light was still on. I don't have any other problems with it, the light mostly. Am I overlooking something? Or do I need to reset the computer? I need help please, this issue is really starting to get on my nerves. Any help would be greatly appreciated. Thanks

 

How old is the battery? Quite possible that the battery has developed an internal short that is causing it to act like a power sink. I'd start with a new battery and go from there.

Dave

 

Hey, thanks man! It is probably the original battery. I was just thinking about that today after I got really frustrated with it. It's doing something new now. Sometimes while it's running, I will try to turn my stereo up past 20 and it won't let me and the stereo panel says "LOW POWER MODE" like it does if you just have ignition power (just battery power) on without starting it. You'd think since I'm a mechanic, that I would have thought about that before I changed a $530 alternator . . . ouch! I'm going to kick myself in the *** if that's the problem. I hate how I sometimes overlook the simple things and go right for the complicated and expensive crap. Thanks Dave, I'll let you know if that does it. If it's not that, what do you think it is? I had some guy on Justask.com tell me that something in the ignition system is tied into the charging system and that I should have my truck hooked up to a scan tool to determine the problem. That sound right to you?

 

It's probably worth replacing the battery if the battery is 3+ years old anyway....

 

actually those earlier ones are known to have bad alternators. We did quite a few at dealer earlier on.

 

I just changed my alternator a few days ago. Until about a week ago, I had no problems with it. The light just kept randomly coming on. It just stays on now and sometimes makes the stereo not go above 20, "low Power mode" message comes on and gives me a headache. I will still change the battery though to see if that fixes the problem. I'm just confused as to when my older alternator was on it, the battery light only came on randomly and as soon as I changed it, it came on immediately and hasn't shut off since, and the battery and stud on alternator are both reading 14v DC while it is running with the battery light on. Is it possible that I just got a bad alternator from the dealer parts department and should get a nother one from them? Thanks for your input on this fellas, I appreciate it. Let me know if there may be another issue that I should be aware of as far as this goes.

 

It's possible that the alt. is bad even though it's new....but it's more likely that the battery is gone, it's original, right?

 

I'd put my money on the battery. AND, I'd only replace it with one of the Interstate batteries that match its size. There is some thing about these vehicles that wants that type of battery. I read some stuff that was pretty detailed but don't remember where I saw it. Hate getting old....
BJ

 

Thanks man! How much do those Interstate batteries run? Does Checker Auto-parts carry it? If not, who does? I live in Hawaii and everything is expensive here and the dealer here is even more expensive. Any ideas?

 

I changed my battery and all is well. Thanks for all the help guys.