Check the leakage current of the car, the multimeter is placed in the AC gear or DC gear
Check the leakage current of the car is placed on the DC current, first disconnect the user's power inlet from the general isolation switch, close all the user's electrical load, such as unplugging the refrigerator, disconnecting the pump switch and so on. Put the digital multimeter on the 200M block of the ohm gear, a pen on the load side of the two outgoing wires on one of them, the other pen touching the wall, it is best to touch the grounding wire or temporary grounding wire.
Wait for the multimeter on the display of the number of stable, read out the insulation resistance value of the main line, if the insulation resistance value is less than 0.5 megohm, then the main line problem, if the insulation resistance is more than 0.5 megohm, it can be ruled out is the main line problem.
In addition to battery leakage, the wiring can draw some, there is no absolutely insulated system, in addition many loads are not directly disconnected when the key switch is switched off, for example, the immobiliser as well will draw some current. Conventional car, the general dark current in about 30 mA, because of the installation of many car appliances, static current may be higher, but not higher than 50 mA.
Because the car battery is generally about 60 ampere hours, 60 * 1000 ÷ 50 = 1200 hours, 1200 ÷ 24 = 50 days, that is to say, a battery, in the 50 mA leakage current condition, theoretically 50 days before you can discharge all the electricity, in fact, it is not possible to discharge all of them, generally put a month will not be able to start the car.
Determine the dark current of the car is greater than 50 mA, for example, 80 mA, 80-50 = 30 mA, 30 * 12/1000 = 0.36 watts, you can probably judge what load static power and this closer, such as the static current of the navigator and this closer to the navigation device to find out if the navigator's power is not turned off.
If you can not find what place leakage, you can pull out the insurance one by one, relay, or disconnect some of the load ground, look at what is broken to the place when the multimeter shows a sudden drop in leakage current, indicating that the problem is in this circuit, and then from this circuit, respectively, to disconnect to continue to narrow down the scope of the leakage point has been to find the right.
