Truck will not start

Hello,

Can you possibly upload a video/audio of the noise you are hearing?
Many time the starter can make a high pitch noise if its not engaging.

Here is a basic engine no start guide might be helpful:

https://www.2carpros.com/articles/car-cranks-but-wont-start
https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

https://youtu.be/dCjmRL3p4Cs

Please let me know if you have any questions.

Thank you.

Turns out the noise is my horn.

Does the starter 'clicks' or makes any noise when you turn the key?

https://www.2carpros.com/articles/how-a-starter-and-solenoid-works

If the starter makes a noise then it could be a bad solenoid.

No. When I turn the key the noise that it makes is coming from the horn.

If you try to jump start the truck does the horn still goes off? Sometimes low voltage could make the electrical components act strangely. Let me know please.

We’ve narrowed it down to a dead short. Still haven’t found it. Removed the horn relay and the horn fuse and the horn would still make noise. It’s back feeding through the ground somehow.

Hello,

I have attached the wiring diagrams for the horn as well as few other diagnostics tips.

Any questions please let me know.

Thanks.

The horn isn’t the problem. it’s a by product of the problem.