Hi Ferarristi, I just got a 1982 Ferrari 400i A and my horn is not functioning. Trying to do some troubleshooting, and I am stuck at the no. 1 step (besides checking fuses) - locating horn compressor. According to manual, oil drops should be applied into the blower unit as maintenance. I am fully lost to where the location is. I did not find it behind the bumper grill. Thanks for any suggestion.
Compressor is bolted on the front of the left fender. There is a relay for the horn. If the steering wheel button works, you should hear the relay "click" when you press the button. If you do not hear the relay, then you problem is on the steering wheel.
If I assume you are in the US, The air horn may have been disconnected and a "conventional" horn installed in its place. I believe in those years air horns were not legal. My air horn was still fully installed, only the wire re-routed to a Hella horn. My compressor and horn were both behind the grill. When checking wiring, remember the wire in the steering column to the button is a GROUND wire. It is real easy to test just by grounding wire to anything. Wire in column is light purple and you can find a connector where column goes just under the dash. (I spent a lot of time getting my horn NOT to honk.) Ken
Assuming the above may have failed. Check and clean the ground connection inside the horn button inside the steering wheel. It was my problem and solution.
If you still have a pair of air "trumpets" behind the left grill area, follow the pressure hoses back to the air compressor, a small cylinder about the size of a soup can. There should be a hose going to the horns, and a second hose going up to the top of the inner fender as the "intake" hose. Disconnect the electrical connector, hoses and remove the pump. The rotor inside the pump end might look like this if the unit has not functioned in awhile. Clean the housing and rotor and vanes, keeping them in the same position and alignment if possible. Add a minimum of oil over everything and reassemble. Test with a couple of wires off the battery and hope its spins, re-install with new hoses and make sure the intake hose will not be drawing rain or moisture from anywhere. That should fix the mechanical portion, the rest is all electrical. Gary Image Unavailable, Please Login
Thanks guys for help, found it. The button was the problem. Some messed up repair was made (see picture). Can't see how this "repair" could ever have worked, the central part never gets into contact with the wired outer metal circle. The horn works fine when wired, I need to figure out my own fix. Image Unavailable, Please Login Image Unavailable, Please Login
2 cent fix, 3 minutes. Works like new. Thanks. IMG_20210516_092325.jpg Image Unavailable, Please Login