Today the battery is dead but yesterday was fine. Didn't leave any accessories on and the weather isn't colder or hotter. The alternator has been goofy lately. Charging strong one day and not so great the next. Can run without the battery but if I turn the lights on it tries to die. Will the alternator being the way it is cause the battery to have a draw?

 

Yes, it can. I went through a new battery, all new cables, cleaned the grounds, and new starter before replacing the alternator that benched good three times. As soon as I replaced the alternator all my starting/charging issues disappeared.

Roy

 

Thanks Roy. Imma try it.

 

Alternator is on the way out...same exact issues my 90 just had, Original Motorcraft alternator made it 21 years...lol. I coughed up for a replacement MC one too...no more cheap parts house crap if I can help it.

 

Ok so I traveled from Dallas to Colorado Springs. Before Ardmore Oklahoma my alternator started charging better than ever, that was before it got dark so no electrical load. It never crapped out and never dropped as low as before. Thank God. Well I bought an alternator on my way through OKC just in case. So I'm in Colorado and it seems to be fine. But imma keep the new one just in case.

 

What is likely happening is your alt is producing little power. The long highway miles at high speed with little load was fine to charge the battery over time. When you do short runs there is less time to build a charge. Also stop and go slows the alt speed and uses brake lights. To be sure you can have the alt load tested buy sience you have a new one anyway is just replace it and check all the connections then have the system tested. Make sure your battery is still good after all the drain its had.

 

a good alt does no good with a dead battery. if you already got the new one put it in. i also second getting the battery checked afterwards. i ignored a alt going bad and it killed a cell in the battery. if your confident enough rebuild the old one and keep that as a spare

 

Should've mention it but I went with a AC Delco. You can't go wrong with a MC, always a good choice. I had the same issue, it would charge on long drives and die after a few short ones. Alternator was simply not putting out enough to keep the battery charged. Still don't understand why it continued to test good at the local PS (wasn't even borderline). But that was the problem.

Roy

 

K. Imma keep the new one and build the old to be a high amp. I have a lot of lights and plan on buying a new winch.

I have an Ultima red top, and it has only killed the battery fully twice. So I doubt the battery is bad. Gotta dig out the cheese grater I guess. Incase no one knows what I'm talking bout, I mean the old school battery load tester.

 

Yep that's the way to go. Either old school or high end. Those parts store units suck.