I noticed about a week ago that my truck was struggling to stay running and that my battery gauge had fallen to the red area and my battery light was on. I tested the battery and it's fine, only about 6 months old too. The alternator tested fine and all the connections looked good. Yesterday I checked all the grounds that I could get at and cleaned/ tightened them up. Now my gauge is always in the red and my light is on constant. It was acting like a bad ground but now I got nothing. It's running rough when near idle and if I come to a stop it tries to die on me. Any one else had a similar issue with their's or any ideas on a cause?

 

A friend of mine had that problem not too long ago. His problem is not really going to help you because it turned out to be the alternator. After the new alternator the problems went away.

 

My alt went last week on my black 99 after a good dose of mud. The battery light came on but I made it home before the gauge reached the red. Changed out the alt and all is fine. Sorry not much help.
John

 

How did you test the alternator? Did you use one of those home tester thingies, or did you take it to an auto parts store to have it tested?

I suggest doing the latter if you hadn't yet. Those home testers are great at some things, but I highly doubt it could really tell you if the alternator is your problem or not, because it sounds like it's either that, or a really bad connection. How much cotorization is on the battery posts and wires? If there is a lot of build up, it can start making some weird stuff happen, plus kill the truck.

 

Well I thought my dad had tested the alternator but apparently hasn't so that is what I'll check next. We do a lot of car repair and know what to look for and I personally trust myself over someone at an auto store. Thanks for all the responses.

 

Well, thanks to everyone. It was definitely the alternator. My battery had more voltage than it was putting out. I think the real problem though was that the output wire was cooked. The rubber boot on it had melted and the terminal was nearly gone. Got a new alternator and terminal and it goes in today!