Hello all, first post, came here for advice. I have an 03 Silverado I bought used. After about 3 weeks, the horn quit working, then a couple weeks ago, I swapped out the factory CD deck for an aftermarket, and it wouldn't power on, so I put the factory radio back in, and it wouldn't work as well. I'm figuring the issues are related, but not really sure what it could be. All fuses and relays appear to be good. Any advice would be greatly appreciated, thank you

 

Welcome from Florida. You say the fuses and relays appear to be good. Did you test them or did you just look at them? You can't tell by looking, They can look good but be bad at the same time.

 

With the radio, I actually went and bought a new fuse and put it in, and it still didn't work. Thought it may have been the fuse on the back of the radio I bought, but that was good too. There is a ground wire coming off a wiring harness that is bolted to the top of the firewall that looks like whoever owned it before spliced to fix it. Not sure if that has anything to do with it, because it was loose and prevented the truck from starting.

 

If the horn quit working weeks before the radio swap then they are not related. Did the factory cd deck work before you swapped it out? Sounds like something came loose during the swap or maybe you are correct and the ground wire is loose.