Originally Posted by Al Capwned
He says the coolant and oil are good. What else could be causing the horn?
You keep using the word "horn". Do you mean the actual horn, or do you mean the "buzzer"?
Low oil and coolant trigger the warning buzzer. If your horn is actually blasting, you possibly have an issue at the trigger in the steering wheel, faulty alarm, etc.
What fuse did you pull?