Bought my 89 back in august. Horn hasn't worked since. Bought a new horn relay, but couldn't find where the relay actually sits. Any ideas? If the relay doesn't fix it, are horn assemblies hard to come by?

Ok a few questions and some tips.Did you check the fuse in the box below the dash.When you push the horn does the relay even click.Lastly have you tried removing the horn and sand down the metal for a good ground.Do the simple items fuse and clean the horns brackets and wire hook up.IF the relay does not click DOES not mean the relay is bad.You would have to remove the steering wheel to verify and or clean the horns contact metal is clean and touching the metal ring for it to initiate the horn relay and make the horn work.Get a steering wheel puller low cost and easy to do.The relay for the horn should be on the driver side fender (behind the battery) at least on my 85.I doubt the relay is bad but your contact under the steering wheel and or the horn maybe at fault.I bought my horn from either autozone or napa and it sounds like the typical GM horn at least the one I bought.Any further questions just ask.In short my horn went bad and my contact under the steering wheel needed to be cleaned to fix my horn issue.Most 1s-2nd gens do not blow fuses for the horn on recall and the relays generally do not fail,however either can happen.

If by horn assemblies you mean a "whole" horn, no not at all hard to come by lol. I was at Advance Auto a few weeks ago and picked up a new one for I think ~$20. One of the problems I FREQUENTLY run into when my horn doesn't work- is simply that it has come unplugged. Maybe its just my horn that does the whole unplugging-on-its-own thing, but it just goes to show to look at the dumb stuff first! ('91 Cav VL)

An easy way to check the acual horn is to test the wire for 12v when the horn button is pressed. If the wire has 12v and the horn isn't working, the horn is dead, or so far out of tune it won't play (however, you most often you will still hear it buzz a little). My 92 had a dead horn, no sound at all. I got two off of junkers and one of those was out of tune, the other worked fine and is on the car now. If one is simply out of tune, you can turn the tuning screw to get it working again, most times. The tuning screw is the little screw that looks like a TORX bit head. Easist way to do it is to take the horn off and run a jumper wire from the positive battary connected with aligator clips to the horn's connector. Turn the screw a little (1/8 of a turn at a time) and ground the horn's bracket to the chassis. If it sounds a little better, but not quite right, turn the screw another 1/8 turn, etc. If it sounds worse or doesn't sound at all, turn the screw the other way. Just turn the screw very little at a time. A little goes a long ways with these tuning screws.

If you don't have 12v at the wire that plugs into the horn's connection when the horn button is pressed, then troubleshoot as the other post suggest.

1. Found 3 Relays on the Passenger side fender. Can't get the buggers off
2. Can't find the horn. Looked up down the engine bay and from underneath.
3. I push the horn, but I can't tell if the click is from the relay, or from the old plastic. Also can't tell if the contacts are even connecting.

1. The 3 relays are probably the fuel pump, A/C and heater blower, I think.
2.The horn is probably on the side of the fender behind the bumber in front of the wheel well. It is easiest to get to from under the car. You may need to take off the plastic cover that goes from the bottom of the fender to the chassis. I don't know what side it is on, as some Cavaliers had it on the right and some on the left, but on them, they are in the same place, just different sides. I imagine they are in the same place on a Sunbird, but not 100% sure.
3. Take the horn button (cover on steering wheel off. Pull the wire off the cover and touch the end to the steering wheel shaft. If the horn blows or you at least hear a click, you know the relay is good and there power to it.

IOh yeah, I would check on the drivers side for the horn, since your car is an 89. I believe the Cavalier's was moved from the left side to the right side in 1992 when the cars got ABS and the windscreen washer fluid tank was moved to the lower left front fender area (where the horn was on earlier years).