Thats unfortunate . I don't prefer buying batteries at these discount stores I buy Interstate batteries myself.
Left batteries disconnected over night and after 12 hours read 12.7v and reconnected amp draw reads 1+- but today was an above freezing day. More than likely the cause.
But Pulled the alternator pulled the batteries. Batteries check good. Alternator checks good. Hook everything back up and do an amp test on the alternator again and at 1200+- rpm with everything on running about 67amps at 14.7v. Same test at 1600+-rpm gets 74 amps at 14.8 .
Isolated each circuit and used a test light.
-disconnected secondary battery
Disconnected neg on main battery and closed the circuit from neg cable to neg on battery with test light(test light on)
-pulled each fuse one at a time. Literally every fuse.
-light stays on
-this test yealds no results.
Going to let sit ove . Night again and see if its the cold weather bringing the v/amp down so low.