Battery draining while idol

Hi @sam48298

With the engine turned off, disconnect the -ve battery cable from the -ve battery post and connect an Ammeter (function of a DMM - digital multimeter) in series connection between the -ve battery cable and the -ve battery post i.e. -ve battery post → Ammeter → -ve battery cable and measure what the quiescent current value is.

Normally the quiescent current for most vehicles is in the range of 50mA-80mA. (mA = milliAmps)

If the current value is greater than this value, there is a parasitic current flowing that is draining the battery.

You need to remove the fuses from the fuse boxes, one at a time and check what the current is with a fuse removed. If there's no change, replace the fuse and remove the next one (so that you don't mix up which fuse goes where) and so on until when you remove a fuse the current value drops to the normal quiescent current value.

This is best done by two people, one removing/replacing the fuses, whilst the other watches the Ammeter. Perhaps also start with the passenger compartment fuse box as this has the lower rated fuses that are more specific to features and circuits, rather than the engine bay fuse box which mostly has the higher rated fuses which then feed the lower rated fuses

Once you've found the fuse which when removed causes the current to drop back to normal, check the fuse information in the fuse box lid or the owner manual to find out what the fuse is used for. Once you know that , you're halfway to finding out what is causing the problem