Battery not charging
Having intermittent problem with my 2000 1500 5.9 4wd. Battery keeps failing to charge. I replaced battery and over 1 month period of limited use, battery was dead. Jump started truck, and after few minutes seemed to charge battery and was able to shut off truck and restart without a jump. Drove truck for about 1 hour with a couple of stops and seems to be charging battery. Drove some more and check engine soon light turned on and battery meter was pegged all the way to the right. Stopped at gas station and shut off engine and battery was completely dead.
Took alternator to Autozone and they said it tested good, lamp/diode, regulator, rectifier all passed. Put alterntor back in and charged battery and is currenty running, but not sure how long it will last. Is there a separate voltage regulator that can be tested/replaced? Any suggestions on what is causing battery to not recharge?
Any suggestions would be appreciated.