2001 Nissan Frontier power drain

Problem: Power draw / loss.
2001 Nissan Frontier XE. 4 cyl.
Mileage 97,000
Had the vehicle 4yrs. Without problem. Replaced battery in January 2019 (defective) and April 2019 (current). Moved from NH to VA. Now I have a power drain. My brother said it’s the battery, had it checked, it checked out good. He tested the circuitry and found a 4.5amp draw. What can it be?

One way to narrow it down is to start pulling fuses one at a time. When the draw drops to normal you have found the offending circuit. Then you start checking components and wiring in that circuit.