Ok guys and gals, I need some help, or at least some direction. I am not electrically enclined, so some of this stuff is Greek to me. I have a 1991 Z28 with electric door locks, windows and hatch release. I keep blowing the 20 amp fuse that services the locks, hatch, power mirror dome light and as far as I can tell, the horn. But not the windows.
I have a spare harness and from the looks of it, the windows and the locks and the drivers mirror all share the same ground- any pointers on where to look for the problem??

When does the fuse blow - when you operate one of these items, or as soon as you plug a new one in?

A common cause is a shorted cigarette lighter socket - might have a coin etc stuck in it.

Thanks SO much for responding so quick! I can be driving and I will hear a 'click' and the fuse is gone. I have pulled the cigarette lighter and taped over the plug, so I am pretty sure it is not that..

Check your grounds, any wire that is exposed could cause fuses to blow, check around your battery, under dash were maybe a alarm was, and wasnt properly remove.

Here's the diagram of the ACC fuse for my '86, it's probably fairly descriptive of your '91. See if you can track it down to a short in one of the devices shown by unplugging them one at a time, if you can.

If you're unlucky, it might be a hacked wiring short as mentioned above. Sounds like the short is intermittent, which are always the hardest faults to find.