Does it have an air bag and if so is the air bag light flashing, Also if it has Cruise Control does it work, if not.
Then the most likely cause is the Clock Spring inside the steering wheel.
You can get a remote horn button from your local parts store. You can splice into the ground wire under the dash going up steering column (Black Wire) to check if right wire just ground it. Then tie into it with one side of the horn button and ground the other side.
If you search the net you will find the clock spring but the cheapest I have found was about $90. I have the same vehicle and found the clock spring as the culprit.