I have some electrical problems and sick of putting in good batteries

Yes the alt. Was bench tested twice now and they say it good ! So I put back on and put new bat in the van and still same thing starts for awhile then will die after drianing the bat. So I had fuseable links checked and all conections and they where all good still run of bat. Till it is to low to keep going ! And the chck chrg. Light remains on ! HUM !

Yes I have a meter ! And yes the old alt. Chck bad when bench tested, now I just checked the bat and alt. When running and alt. Did not come on to charge and bat was running low ! I tryed some thing ! I losened the pos. Cable on the alt. And jiggled around and the alt. Kicked in ! But then would not shut off charged up to 14.87 votls so I turn off eng. And tested the bat was at 13 and turned van back on it ran but soon the bat ran down again to almost 11.4 volts then died ! Alt still not come back on so tryed one more time the prosses I did before and same thing happend

Ok ! I losend the pos cable on the alt. That goes to the bat just to see if the alt would kick in and when moing it around on the post it did kick on the alt. But if I tightn back on and shut off the van and turn back on the alt. Does not kick in enless I losen that pos cable coming off the alt. Then it willl kick back on but wont kick off ! When fully charged ! So I shut van off and start it back up and let it run and it just runs off the bat. Till it dies ! So thats when I losen the nut and jiggled the pos. Cable

And so the voltag reg. Is built in and should come on when volts are low but is not kickn in intill I losin the cable on the alt. So what do u think