hey guy actually when i was looking at that i found something wierdDude, Trying to help you out here. Its hard to do it over the net. The space in your fuse block shouldn't matter. If the radio was working before, and you are using the harness, then your power source will be the same as before. No matter what HU you use. Here is a link to your wiring diagram. Make sure that all the wires are correct. I had a wiring harness one time that on of the wires was switched. Easy fix but confusing at first. http://www.installdr.com/Harnesses/GM-Wiring.pdf
http://forums.caraudio.com/vb/showthread.php?t=135497Give us a update d0o0o0od. Did you try conenctin the yellow and red together in the buick? Try running the wire to the batt, and make a new ground. i think this is your best bet.