CD/Radio stopped working in my winter beater

Switched power is setting the test light off when key is on…key off, no light. Constant appears to not set the light off at all…assuming I’m testing properly. Is it the yellow wire labeled ‘memory’ that is constant??? That’s the one I’m testing…

Yes, I checked with the fuse in…and visibly it appeared to be good. Tomorrow I can make sure the fuse itself is good.

While searching the interweb for research I came accross this:
If the radio does not power up after installation, be sure to check the factory fuses
to see if they are blown. If the fuses seem to be okay, take the radio out to the
vehicle battery. Connect the red and yellow wires to the positive post and the black
ground to the negative post. Turn radio on to see if it works. if so, recheck the yellow
and black wires in the dash.

I tried this with the head unit and it would not turn on…took both the red and yellow and twisted these together for the positive terminal; black to negative terminal. When connecting the red/yellow to the term it was spark a bit. WTF…