You have a short circuit. You need to figure out if the short is in the cabling or the amplifier. My guess is that you have the power wires backwards to the Profile amp.
You can check this using your multimeter. Use the multimeter in continuity mode (don't know how to use it? Watch this
handy video). Most digital multimeters have a setting that emits a sound if you get continuity (which would read as zero or near zero ohms of resistance) so you can check wires without looking at the meter. Test your meter first by touching the probes of the multimeter together. On my meter, when you set it to test continuity, I get a "0L" reading when the probes are not touching and a .9 ohm reading when they do. It varies a bit, but never goes over 2.5 ohms.
Put one probe on your distro block + side. Put the other probe on the wire you are plugging into your amp. You should get continuity. Tag that wire with a piece of tape and mark "+" on it so you don't mix it up.
Do the same with your ground wire. One probe to ground, one to the ground wire you are running into your amp. Again, you should be getting continuity. That confirms that each wire is hooked up the way you think it is.
If both are set properly, connect them to the battery, put your meter in voltage measuring mode, test that it is working properly by touching both terminals on your battery (should get 12 volts or more), and then put the positive probe on your meter to the + wire for the amp and the - probe onto the ground for the amp. You should see 12 volts or thereabouts.
You know now that your wire harness is working and that you have not mixed up the wires.
If you found no errors, test the amp to see if it has a short in it. Put one probe on B+ for the amp and the other to GND. If you get continuity (again, either zero or very low resistance), the short is inside the amplifier. If not, you are okay to connect the wires to the amp and try it out again.
You're still not out of the woods even if that works. Before you hook up your other amp, do the same checks and make sure you aren't somehow mixing + with - in the wiring harnesses.
And ALWAYS use a multimeter when connecting stuff. NEVER trust the wire colors or even looking at it with your eye. Always check and you'll never blow stuff.
Plus, using a meter makes you look like you know what you're doing. Need to make sure there's no power in that light switch? Check it with your meter first! It may keep you from getting killed one day.