battery draining

[z71MudDog]

in my 1984 k5 chevy blazer the battery when fully charged completely drains within a few hours it only started when i didnt drive it for about 2 or 3 weeks.i heard someone with a '91 s10 trailblazer had the same issue and it was a 30A metal fuse for power windows or something..i checked all the fuses (20A and lower) all were good but the courtesy lights and cigarette lighter replaced it lights work but still keeps draining out.is it a short orwhat? i have no idea any help much obliged

[00Silverado4x4]

I'd start with a battery test (Advance, Autozone, wherever) If that's good then get a clamp on ammeter to test for draw & start pulling fuses until the draw goes away. This way you can isolate the circuit that giving you problems.