Ge yourself any old 12V automotive relay off amazon like this: https://www.amazon.com/Pack-EPAuto-Relay-Harness-Bosch/dp/B017VDI0GY/ref=sr_1_3?dchild=1&keywords=automotive+relay&qid=1603511065&sr=8-3
You'll notice the relay terminals (86, 87, 85, 30) are all clearly marked on the relay and...