Do you toot-toot too much?
No, I am not talking about flatulence; that’s a problem for you to talk over with your doctor. But if your problem is that the horns on your old car seem to have a mind of their own and toot at unwanted or embarrassing times, or don’t toot when you want them to, we may have a solution for you.
We talked in an earlier article about restoring and tuning your tooters. The horns themselves don’t decide when to honk. That is the function of the horns, the horn relay, the horn button and the nut behind the wheel. The horn relay supplies the electric current from the battery to the horns. The horn button controls the horn relay and, of course, the nut behind the wheel decides when to push the horn button or ring.
Because the horns require a lot of amperage, heavier wires are needed to supply ample electricity to the horns themselves. The relay acts as a heavy wire connector directly from the battery to the horns. The relay consists of a low-amperage electromagnet that closes a set of high-amperage points, allowing the direct connection from the battery to the horns. All the horn button does is provide a ground that activates the relay.
If the small wire going down through the steering column grounds anywhere, the relay closes and the horn honks. On the other hand, no ground, no toot. This wire and its terminal at the top of the column must be well insulated against grounding except when the horn button or ring is depressed.
The horn button is usually held away from grounding by a cone-shaped spiral spring. If this spring breaks or gets weak, the horn will tend to toot on its own. If you need to replace this spring and can’t find one, here is a little hint. Find an old flashlight that has the same shape of spring. If it doesn’t fit exactly, you can usually bend it into the right shape.
There should also be some foam rubber insulation that keeps the mechanism from shorting out and also holds up the horn ring, if so equipped. This rubber tends to rot and fall apart. You can always find some foam rubber stock and cut a new one. Sometimes it will take more than one thickness to insulate properly.
Don’t forget the small insulating ring between the top wire terminal and the steering post. If this is broken, you may be able to slip a rubber O-ring (or two) over this terminal. If you are replacing the wire going down the steering column, you can use heat-shrink tube to make sure the top terminal is insulated from the steering column post. You can use a continuity test light to make sure you are getting a ground when the button or ring is depressed.
Next you will want to check the wire from the bottom of the steering column to the horn relay. A short here can cause a toot when you don’t want it, or, if broken somewhere, no toot.
Assuming that your horn button is working well, we now have to look at the horn relay. This is normally on the firewall in the engine compartment. It is a small black box that is sealed, and has one or two mounting screws and three wires connected to it. If you can tap this and the horn blows, it means the relay is defective and needs to be replaced.
As a matter of fact, if you have the slightest concern about this relay, replace it. They are quite inexpensive and readily available at most auto parts stores. Just be sure you get the right voltage. The three terminals are generally marked “H” for horn, “B” or “P” for battery or power, and “S” for switch. The battery connection is usually the center post.
If you are ever out on the road and your horn starts honking on its own, you can disconnect the battery terminal or the horn relay and do your repairs when you get home.
Well, there you are with good working horns again, but, if you are out driving and the horn accidentally toots when you pass a good-looking girl in a tight green sweater, you can tell your wife that it must be the horn relay acting up again. My own experience tells me that will only work once or twice at the most.
See ya later,