Intermittent Battery Warning Light

[gamanaja]

I have a 2002HD with 8.1 engine. The battery warning light seems to randomly flash on and off at times as I drive or at idle. It does not seem to have a pattern to when it does it. I have disconnected and cleaned the terminals at the battery which seemed to help at times but suddenly it acts up again. Replaced the positive terminal fitting. It can be trouble free for miles and then start to act up. I noticed that if it comes on while at idle if I rev it the warning light seems to pulsate a little. Not sure what to do. have had battery checked and alternator checked while running and at rest ... all seems fine. Should I consider a new alternator? Vehicle has 103,000 miles on it. Still original alternator. Mechanic says it may be the diodes in the alternator acting up. Travel a lot and don't want to be stuck somewhere. The light stays on for different lengths of time but usually short few second periods then goes off and then maybe back on. Readings on meter seems to be fine.

[gmtech4]

charge up the battery ,then have it load tested,if it fails...replace it .

 

you can have the alternator tested also for output under load and if it fails.....replace it .

 

or replace the alternator and battery ,

 

testing can get pricey so get a quote before any work .

 

let me know

[gamanaja]

The fella at our local NAPA store put a tester on the battery and alternator and went through the sequence of tests with and without loads. Battery read very strong and alternator showed no problem and was charging. BUT of course the light was not acting up. I have put a volt meter on the battery post connections when the light is acting up and noticed no difference in any readings while light was on or off. Out put from alternator reads over 14.

[TexasAl]

If your truck is starting easily, which I assume it is since you did not say anything about it, I am thinking it has to do something with the cluster/voltage meter. I wouldn't worry about it. If the truck shows signs of hard to start, then get it checked out again.

 

 

Al

[gamanaja]

The truck has no problem starting and runs great. Just the light is annoying. Is the cluster/voltage meter built into the alternator or something thats separate and part of the dash instruments?

 

Thanks