Hello, there's a parasitic drain test you can do. First lock the car up and allow at least 30 minutes for the modules to go to sleep. If it has a hood latch sensor, you have to latch that with the hood open, same with the doors or some of the vehicle's modules will not go to sleep, and you need access to all the fuse panels. Anything that stays on, any lights or latches that aren't latched will keep a module from going to sleep. After you do all that, take your multimeter and go over each fuse, on voltage setting. Any fuse that reads any voltage drop (voltage) is a fuse that has current flow going through it. This way you don't have to disconnect the battery for this test. Once you find a fuse with a voltage reading, that will be your circuit that's drawing on the battery. If it's draining that fast, you'll have a higher voltage drop on whatever the problem circuit is. But you have to remember to latch the door latches if you're going to have the doors open to get to the inside fuse panels. Anything that will keep a module (computer) awake or powered up. Lock the security system too.
This hood switch is an example of what needs to be latched so the vehicle thinks everything is closed and locked. Then it will power down the modules and go to sleep. Communications on the CANbus networks will stop, this is a tough test, you'll need a wiring diagram of whatever fuse you find that has voltage on it. The fuses should all read 0 volts when the car is off. and locked up, powered down. Any questions just ask. Be patient with this though. Give the car 30 minutes after locking up and the security system is activated.
Here is a great video to show the whole process:
https://www.youtube.com/watch?v=lRcj1fQcWwU
https://www.2carpros.com/articles/car-battery-dead-overnight
https://www.2carpros.com/articles/how-to-use-a-voltmeter
Image (Click to make bigger)
SPONSORED LINKS
Tuesday, January 25th, 2022 AT 2:13 PM
