All you have to do is get the correct voltage to the spot I added the wire too. I think it's 12V, but the wires are blocking the view. use the correct relay and add a momentary button and count off the seconds depending on how cold it is. Max should be about 7 seconds. I've been doing it this way for 2.5 years or so and it's always worked great.
Apparently I recorded this Dec 19th 2021. I dont remember if i've already posted it on my channel. Hmmmmm lol