BMW Seat wiring for el Camino

Here are the parts I used to make the 2007 BMW 328i bucket seats work in the 1968 el Camino: 12V to 5V 3A Step-Down Waterproof Miniature DC-DC Converter Power Supply Module: https://www.amazon.com/dp/B07MYPCM73?psc=1&ref=ppx_yo2ov_dt_b_product_details NE555 Pulse Frequency Square Wave Rectangular Wave Signal Generator https://www.amazon.com/dp/B018INS9QM?psc=1&ref=ppx_yo2ov_dt_b_product_details Project Boxes ABS Plastic Electrical Project Case Power Junction Box Black 2.76 x 1.65 x 0.71 inch https://www.amazon.com/dp/B07PWQVTY2?psc=1&ref=ppx_yo2ov_dt_b_product_details Dupont2.54 Pre-Crimped Cables and Connectors (needed to connect the square wave generator board) https://www.amazon.com/dp/B087N4GY8Z?psc=1&ref=ppx_yo2ov_dt_b_product_details 12V Auto Waterproof Fuse Relay Box Block Kit https://www.amazon.com/dp/B08KHVHLL5?psc=1&ref=ppx_yo2ov_dt_b_product_details