Coke is very corrosive. I would not pour coke on anything in my engine compartment. I hope you washed it out well. You did not show where the solenoid is??? Thanks anyway.
I’ve had the same problem 3 times already, the first time I had to grind off the paint on the body where the negative ground hooks to and it worked, 2 months ago same thing but my battery was swollen from the heat and got a new battery and it worked, today same thing cleaned the terminals and swapped the battery and still nothing, I’ll try the relay we’ll see 🙏