GMC Repair: dead battery, excessive amperage, amp meter

Question
i have a 2004 GMC Envoy  if i do not drive it for 3 or 3 days  my battery goes down. replace battery 8 months ago for same reason .  i drive it for about 20 miles nonstop once a week   some times much more . will make couple short trips to store a week .  Please help if you can  THANKS  Robert

Answer
Hi
Battery should last longer.
First, I would have the battery checked, just to totally eliminate it as a possible cause.
It MAY have a weak cell.
After that a parasitic electrical drain test would need to be performed.
Don't know how electrically savvy you are. You will need to check the amp draw of the system at rest.
I hook to the negative side, put your amp meter in SERIES with the negative terminal.
Should be slightly high at first for about 1-5 mins. (high = 1 amp (1000ma)and should as modules go offline, work its way down to anywhere from 15ma to 30ma. IF NOT, start pulling fuses at the underhood fuse box, until the excessive amperage goes away down the the acceptable levels (lets say 25ma).
at that point, whatever load is on that fuse is most probably your draw.
Hope this helps