I bought a crappy Dual DA301L from a closeout sell for $20. This was tested at 130W rms @ 4ohms and 205W RMS @ 2ohms. I want to pair this up have a 10" sub. Before installing it I want to test inside my car to see if it's worth installing it.

The problem is that the wiring is very weird and different from installs I have done before. The power connector has 2 16ga red(+) wires and 2 black(-) wires. It also have a blue remote but the weird thing is that is have another ground wire under the remove for a total of 6 wires.

Here is a picture of the connector:

I have a separate lawnmower battery that I am using to test this. I joined the 2 + wires and connected to a 10ga wire. The same with the - wires. I connected them to the battery. So far so good. When I clamped an 18ga wire to the 16ga remote and then jumped it (just for testing) to the + side of the battery, the 18ga wire fried in a sec. I was like WTF, there isn't suppose to be to be so much current going to the remote.

I have jumped the remote from the Battery + on other installs for testing without any issues before.

Did I just shorted something? (most likely)
How should I use the GND wire under the remote wire?
Anything wrong here?