Hi! I have a 2012 Toyota Yaris. I have the Pioneer 7" DMH-1500NEX radio. I bought it from BestBuy, so I also have the Metra - Wiring Harness for most 1987 and later toyota/scion vehicles (model 70-1761).

I've watched many tutorials and videos online, but I've mostly seen everyone using the Toyota ISO harness, which doesn't require any wire-work except plugging things in. Metra supposedly makes life easy because you just have to match the colored wires together, but there are some wires that don't go together or where I'm unsure of putting them. For example, the thick black "ground" wire. I know it's probably supposed to touch metal to "ground it," but I don't really know where specifically. I also don't know what to do with the wires that don't have color codes.

I've also never done anything with wires, so that's a plus! I don't own crimpers, electrical tape, or butt connectors, and I've never soldered or spun the wires together before.

BestBuy has been such a pain for a simple purchase, so I really want to do this myself. I feel very out of my depth because I've never worked with wires before though. I just want to connect everything in the right place, not ruin anything or cause problems, and have my new functional radio. :( The Metra harnesses are just so confusing to me.

If anyone has any advice on how to do the wiring, I'd appreciate it. The Metra website didn't exactly have any tutorials or anything, just one video where it showed how to put the wires in a butt connector, which helped a lot, but it doesn't say what to do with the ground wire or another major one. I assume I can't just leave anything hanging freely if it should go somewhere.