I have a 1995 nissan pick up truck, and im just not sure what to check next

What is your question?

I have replaced the battery alternator and starter,I have replaced the battery terminals as well. The truck seems to run fine for a day or two then we are right back to the same problem It looses power, lights flickering, radio cuts out. Last night it started and ran fine drove it about ten miles and stopped to get gas. When I came out my battery was completely dead, jumped it off made it about 3 miles down the road and it started loosing all power again. I have checked to make sure nothing is drawing on the battery I just don't know what else to check.