Added an amp to my car and only used 18 gauge wire from the speakers, s***ts a stinking

drip or drown

How much amperage is the amp drawing.

You very well might set your car on fire for such a dumb movem

if you've gotta ask...

It may not idk.

I'm one of my old cars years ago I figured out why the subwoofer cut off suddenly one day, the wire leading to the fuse melted itself right at the fuse connection.

The fuse never broke, it just melted the connection off around it.