battery light on then off

so brand new battery...preventative for winter and this old one was dated 6/21
been no issues but its not my daily driver. today drove for about 30 miles with several shut downs and starts...all fine. then got home and a few hours later started it to move and battery light came on. shut off and then restarted no light and ran about 15 minnutes...no light. shut off...sat half hour... restart no light...torque pro showed 13.4 volts. my son needs to borrow for a week.

Ideas ?

 

Possible that your cables are loose, you didn't tighten them.

The alternate possibility is your alternator is getting fucky.

Doublecheck the cables, wiggle, make sure they're tight. If tight, keep an eye on it, if the light comes on again, see if you can verify your voltage before turning the truck off. If it's low, your alt may be going out. Actually, if the light pops on again the alternator may also be going out, but ...

 

My first thought was alternator also. It holds the voltage regulator for the whole entire truck

 

thanks,,,but I cleaned terminals and connections when put new battery in...and when this happened this afternoon I checked my connections and terminals...all tight...guess my alternator is on its way out, hope it gets threw the week with my son borrowing...

 

The alternators are not hard to change in these trucks