Door Speaker Help!

[Contr_eras]

Hey everyone! It took 2 months, but I finally got the sound system working. I kept my kicker door speakers and my stock dash speakers. I'll run through my entire process from start to finish and post a TLDR at the end. I started with just replacing door speakers with Kicker 225 W CSC5 speakers. after this I had no sound from the door speakers, but the dash speakers still worked. I ensured the connections, and they just wouldn't work. After this and some discussion with smarter people than me we decided to change the amp. I bought a Kenwood Class D bridgeable multichannel amp at 50 watts per channel at 4 ohms. I didn't want to go crazy on the amp I don't need the craziest sound setup and wanted to protect my dash speakers so I didn't go higher on the wattage. I ordered some adapters to go from the head unit to go to a line out converter to change to RCAs and finally into the new amp. After doing this I now had no audio from any speakers. I once again verified all connections, still no luck. More discussion with smarter people and we decided to replace the head unit. I went with the VDO Continental European style radio head unit and put than into. had to re-wire some wires on the adapter since some of the pin outs were different on the VDO and stock head unit. It worked! But I only had 3 speakers, one door speaker didn't work. After troubleshooting we determined that one channel on the amp was fried. Lesson here: Don't buy open box amps from Best Buy. One new amp later and everything worked great. I don't currently have radio just Bluetooth and aux since the stock head unit uses some sort of non-standard antenna connector, but I'm personally not too bothered by this.
TLDR: Be ready to replace your amp and head unit if you want to change door speakers, and DONT BUY OPEN BOX AUDIO COMPONANTS FROM BEST BUY.

Links to the major components I bought for this project (there's some smaller stuff like cables and adapters I bought as well but I'm not going to list them here):
https://www.bestbuy.com/site/kicker-cs-series-6-1-2-2-way-car-speakers-with-polypropylene-cones-pair-yellow-black/6333353.p?skuId=6333353
https://www.bestbuy.com/site/kenwood-class-d-bridgeable-multichannel-amplifier-with-variable-crossovers-black/6330250.p?skuId=6330250
https://www.amazon.com/VDO-Continental-TR7412UB-European-Bluetooth/dp/B08D2R48HZ