Parasitic Power Drain

[apache238]

I have a 2000 Sierra 2500 that has been showing signs of a parasitic power drain. I "think" that the drain is coming from the BCM. After waiting for all the computers to shut down - 10-30 minutes, there is a .03-.05 amp drain, that I can isolate to the TCM fuse under the hood. Everything I read tells me that this sends power to the BCM.

 

So here's the question: How much power should a healthy BCM draw...and for how long? If I recheck at 60, 90, or even 120 minutes should the power draw be at zero?