A parasitic draw is a continuous drain on a vehicle’s battery, even when the vehicle is turned off. There are a couple of ways to check for a parasitic draw.
One way to check for a parasitic draw is to use a multimeter. First, set the multimeter to the DC voltage setting. Then, connect the positive lead of the multimeter to the positive terminal of the battery, and the negative lead of the multimeter to the negative terminal of the battery. The multimeter should read the voltage of the battery. Next, turn off the vehicle and wait for a few minutes. The voltage reading on the multimeter should drop slightly. If the voltage reading drops significantly, it is a sign that there is a parasitic draw.