One of our readers sent in a question about a problem with his horn. Apparently, he replaced his steering wheel and now his horn doesn't work. Here's the inquiry:
"I need advice on how to fix my horn. It started when I changed to an aftermarket steering wheel. Sometimes it works, and sometimes it doesn't--very inconsistent. I know it's not the relays or anything, I think grounding problem nga talaga kasi when I push the horn button long enough, gagana siya for a period of time and then after a while of not using it, mawawala naman."
You sir, sent your question in to the right place. I change steering wheels quite often, and I run into this problem regularly.
Your problem could be a ground or a connection problem. However, you didn't mention if your car is relatively new car or if it's old. This is a very important point because new and old cars have differences in the horn connectors and contacts.
Newer cars have what you call a clock spring or a spiral cable. A clock spring is a device that allows a steering wheel to rotate while the various switches like the horn, stereo, and cruise control remain connected. This is done through a ribbon cable (a wound-up wire) contained in the device. Now, if you changed your steering wheel, this clock spring's connectors may have come loose or the clock spring itself may have been damaged in the process, and you might need to fix or replace it. A clock spring is nothing but a fancy extension cord and a continuity tester should be able to determine if your clock spring is in good working order. Just check the soundness of the connectors and for continuity on this device.
Older cars, on the other hand, have a copper contact ring on the steering wheel hub and a small copper contact spring on the steering column. These two require a good connection for your horn to function properly. If the spring tension is weak, the contact between the spring and the ring may be intermittent resulting in your horn working just some of the time. You need to make sure that the spring and the ring are making good contact throughout the range of movement of the steering wheel from lock to lock.
Aside from the methods mentioned above, you might want to inspect the horn itself as it is mounted to the front of your automobile where it is exposed to harsh elements. Like you mentioned earlier, it could be a ground. And if that's the case, you'll have to trace your horn's wires and find the location of that grounded wire and insulate it properly.
Thanks for writing in. Hope this helps.