how to find parasitic voltage leak at batt fuse on 2000 GMC Safari

So the fuse is labeled batt?

according to the owners manual it is called "batt fuse" It is under the hood in the bank of fuses located toward the rear of the engine compartment.

So when you pull that fuse the excessive draw goes away?

yes

I have checked all the fuses under the dash and under the hood and this is the only one that the excessive draw changes on. I just can't find anything to show me how to trace it to the source of the leak.

That circuit feeds the inside fuse box also thats a big feed i posted some info on what it feeds.Also what is the draw your reading?

the reading is .72 amp on that fuse

So is your battery just going dead while sitting over night?

Yes sometimes before overnight. i.e. I park it at work at 9AM - If I don't start it by 3PM it will not start at 7PM. Have checked voltage on charger and if not charged overnight it loses at least 20 percent of charge

I have even seen window switches cause parastic draw before so sometimes you really have to check everything.

That brings to mind that a while back my door lock quit locking automatically like it used to when I got up to a certain speed. Do you think that could be related also? I'm not sure how to check all this stuff out. Is there a good online guide I can find?

The auto lock is a certain program it could have just got programed differently.As far as the switch etc you just unplug parts and watch how it effects the draw on the system.Thats how i found that window switch draw.

Will try your suggestion tomorrow. Also, you said something about the auto lock being a program and it might have gotten programed differently. How can I check what the program is on it?

try holding the door lock button down for 5 seconds see if the horn honks or the locks cycle.

Held the door lock button down for 5 seconds and nothing happened. Tried it both with the key turned on and off.

Then it probably requires the tech2 scan tool which is what the gm dealer uses.Unless it mentions it in your owners manual my info dont say how to program it.

OK thank you

Update - have tracked the voltage drain to fuse #19 under dash. I unplugged it and drain went away. Unplugged radio and overhead console and drain still there. I made a tool to plug into fuse socket with wire attached and inline 10 amp fuse, put it on an external switch and turn switch off. Drain goes away. If I remember to turn this off every time I shut off car it restarts with no problems. Then I turn it back on to get the gages and whatever else it controls to work. Need to find more info on where to go from here.