Have an open circuit somewhere that is draining my battery

What is your question?

Have an open circuit somewhere. Battery dies overnight. Started shortly after son sat in passenger seat and after traveling about 20 miles and 15 minutes seat belt warning dash light and chime started going off. Unbuckled and buckled pass side several times until it finally stopped. Next thing I know the battery started dying Don't remember if it was a day later or week later but that's the only thing I could figure. Have unplug the sensor in the passenger side seat belt buckle and battery still dies. Any suggestions on which circuit to check or module to replace Would they be an error code on an open circuit that the dealership may be able to find.