Originally Posted by Fountainhead

To find the current draw what you can do is remove the positive lead of your battery and connect an ammeter set to maybe 10A scale -Red lead (of the Amp meter!) to the battery and Black lead (of the Amp meter)! to the positive terminal of the car battery lead, and see if you have any parasitic current drain with all lights off, all door closed, etc.
Because you disconnected battery you'll have to reset the window action but I guess you've already seen that because your battery went dead.
I can't think of any way to find the current draw other than verifying first that there is a parasitic drain that isn't in the spec.
I do not know what the current draw is at completely off but I'm sure it's in the 10's of milliamps.
Once you determine the range of current draw you can move your ammeter scale down from 10A to get more resolution.
You might have a brake light coming on or a dome light left on that drained the battery.
I first cut the SWL brown wire then months later I fixed that connection - in anticipation of taking to dealer and getting the Steering lock replaced, but I chickened out and just pulled the fuse. I've had no battery draining/dead issues, my battery is 4 years old.
I just don't want them messing with my car at the Stealership. I've just heard too many horror stories, I'll avoid the Stealership at all cost unless I can't do anything else. Besides, I would simply unplug the fuse after the new install anyway. I've never had a failure and don't have any out of pocket expense for SWL failing anyway.