[baseballfanz]

The relay is in the IPDM box. Use a pair of plier or something if it's giving you trouble
http://www.titantalk.com/forums/2031576-post5.html

 

[baseballfanz]

Thanks. I tried pulling it out previously but it was in there good and tight. Figured I would try and see if there was anything else it could be. The relay seems cheap enough to replace, but is there any way for me trouble shoot the issue (other than checking the fuses) and find out before buying the part? Is this a common issue?

You can try first to see if power is going to the horn itself (use voltmeter).
You can also apply power/ground directly to the horn to make sure they're not bad.