Slow battery drain, procedure for checking?

[Sadie]

Sounds like you’ve already tackled a lot of the big maintenance items—nice work. For the battery drain, the most common culprits on older Toyotas are interior lights (glovebox, dome, or door switches sticking), aftermarket stereos/alarms, or a shorted relay. Easiest way to track it down is with a multimeter: pull the negative battery cable, put the meter in series, and start pulling fuses one at a time until the draw drops. That’ll point you straight to the circuit causing the drain.

[Vinhomes_CanGio]

On an older Toyota Van Wagon like mine, are there common sources of a parasitic drain this large that I should check first?

[timsrv]

The most common sounds stupid, but it surprises me how many new owners don't know about it. If this doesn't apply to you, then just ignore. There are markings on your ignition switch to indicate the position your key is in "LOCK" "ACC" "ON" & "START". The ignition switch must be in the "LOCK" position to be completely off. New owners are often unaware of the little push button right above the ignition switch that must be pushed to rotate to "LOCK". Toyota did not intend for the key to be removable until rotated to "LOCK", but as the tumbler wears it loses it's ability to hang onto the key in all positions.

Based on my personal experience, the next 2 common drains are usually related to the dome light circuit or a failed diode in the alternator. Tim