Door lock module contributing to battery drain

["Grimsrud, Knut S" <knut.s.grimsrud@xxxx>]

Because I have a daily driver DeLorean in addition to my new one that I'm
restoring, my good DMC doesn't get out much during these rainy winter months
(I'm in Oregon, so it gets pretty sloppy around here this time of year).
I've been a little curious about the gradual battery discharge that our cars
seem to be so susceptible to, so I did a little investgating last weekend.

It is well known that the console clock and radio consume a trickle of
current. However, when pulling the radio fuse there is still a slight power
drain (at least on my cars). In fact, after pulling all the fuses my cars
still have a power drain from the batter of around 11mA. This isn't very
much, but is sufficient to slowly degrade a battery over time.

In trying to track down this power trickle, what I found was that the door
lock module on my car draws the additional 11mA of current. I haven't
disassembled or reverse-engineered the module yet to understand why it draws
a trickle current, but it appears to do so. I'm not sure if the LockZilla
similarly draws a trickle current as I only have stock door lock modules in
my cars.

If you suffer from inexplicable battery drain for a car that's stored for
periods, the door lock module appears to be one of the contributors to the
problem. I still need to recheck my measurements this weekend, but it
appears that removing the clock/radio fuse and unplugging the door lock
module may be sufficient to avoid battery drain without the need for
installation of battery cutoff switches, trickle chargers, etc.

Knut