You will need
To check the current drain on the car? alternately checking car circuit with ammeter and comparing the obtained value with a rated capacity of consumers.
Install the ignition key to position "0". Disconnect the positive terminal from the battery and plug in the gap ammeter negative terminal to the contact terminal of the car and the positive to the battery. Set a price scale of the ammeter in the range of 10 Amps. Passing current when it should not be, if available, check the contact circuit of the starter and alternator.
Then set the ignition key to position "Parking". Unplug receiver or other such device, clearance lights, cabin lighting. Measure the value of the flowing current. Slight currents up to 0.1 fмпера. In case of detection of values that exceed this value, should check the power supply circuit of the Parking lights and interior light, cigarette lighter, radio, alarm and heating system and air conditioning. This is done alternately disconnected from the power supply circuit of these devices (you can also remove the appropriate fuse to disable the device) until the disappearance of the leakage current. Then check the circuit of the device, when disconnected which stopped the leak.
Turn the key to position "1" (but do not start the engine!) and measure the value passing through the battery current, it needs to be in the range of 1-2 amps, depending on the type of engine and ignition. If the current greatly exceeds this value, test the leakage current on the car can only be alternate check of all circuits, with their alternate shut-off and metering through the current circuit, followed by checking it with the reference values specified in the documentation for the car.