What is parasitic load test?
The term Parasitic Load refers to electrical devices that continue to use or draw current after the ignition switch is turned to OFF position. This small amount of continuous battery draw is expressed in milliamps (mA). A typical Parasitic Load can be around 30 milliamps (0.030 amps).
What is a normal parasitic load?
A normal amount of parasitic draw for newer cars is between 50-milliamp to 85-milliamp current draw. A normal amount of parasitic draw for older cars is a reading less than 50-milliamp. Anything past these amounts indicates an electrical issue and should be addressed by a mechanic.
Are cars AC or DC?
Most automotive components require this DC charge to work properly, but it is limited because batteries will eventually discharge completely, with no remaining power to give. To address this problem, cars also have alternators.
How is a parasitic draw diagnosed?
Pull the negative off the battery. Put the test light between the post and the ground wire. If the light illuminates, you have a draw. Use the fuse pull method to find the draw; when the light goes out, you found the draw.
Is 12v car AC or DC?
What does 200m mean on A multimeter?
The range switch on the front of the multimeter shows the maximum current that can be measured on that range. The range switch is pointing at the “200m” DC Amps range in the picture. Therefore, the full-scale readout for this range will be about[1] 200 milliamps.
How do you do a parasitic load test?
Turn test switch knob to OFF position (current through meter). Install negative battery cable to the female end of test switch. 2) Turn test switch knob to ON position (current through switch). Road test vehicle with vehicle accessories on (radio, air conditioner, etc.). After road test, turn ignition switch to LOCKED position and remove key.
Why do I have an intermittent parasitic load?
Intermittent parasitic lad can occur because of a memory device that does not power down with ignition off. With an intermittent parasitic load, battery draw can be greater than 1.0 amp. To find and intermittent problem requires that an ammeter and Disconnect Tool (J-38758) test switch be connected and left in the circuit. See Fig. 1.
How many milliamps does a parasitic load run?
It is usually a very small draw so the battery doesn’t become drained. Parasitic loads can run 20 to 120 milliamps. If there is an electrical short in the vehicle or a malfunctioning accessory it could draw more than its normal load causing a large drain on the battery.
Do you need a positive cable for parasitic draw testing?
Some people remove the positive cable to do this test, and that’s fine, but I recommend the negative cable when doing parasitic draw testing. Put your meter on the highest DC amp scale. This might require that you move your test lead to a special location on your DVOM.