Hmmm...2-3 months is a long time. Dont think it would work to do the idea i mentioned.
The only other idea I have (or would do) is to connect a Ampmeter in each fuse on the car and get the Ampere/Milliampere readings from each circuit and compare. That would take alot of time to do though. Sorry but that about exhausts my ideas for your problem.
ASE Certified Technician
ASE Master Tech, 26 years in the field. Virginia State Inspector