I have a 1982 Toyota Tercel with a horn that doesn't work. I have checked the fuse (which services both the hazard lights and the horn). The fuse is OK.
I currently have access to the entire steering wheel where I see two wires (one black and one white) each going to a contact beneath each horn button on the steering wheel.
On the front of the car, there are connections for two horns but only one horn is installed. Each connection has two wires.
How would I go about diagnosing the problem? If it can be simply diagnosed with a multimeter, I'm game.
This was a good start. I assumed that one wire was + and the other was ground. Initially, I had a voltage reading of 0.01 volts DC. When I pressed the horn button, there was nothing. But when I rotated the steering wheel 90 degrees clockwise, the voltage went to 12.42 volts. When I rotated it another 90 degrees clockwise, the voltage dropped back to 0.01 volts. So I put the steering wheel back to "straight" position and rotated counter-clockwise, the voltage never changed; staying at 0.01 volts.
Sounds like you may have a problem with the spiral cable. Thats the cable that runs through the center of the wheel. Its wound sort of like a spring that winds and unwinds as the wheel turns. That way you can spin the wheel and have wires for the horn, cruise, lights, or whatever else. When it gets old it will start to crack when the wheel is in certain positions. Sounds like it from what you're describing.
Sounds like you may have a problem with the spiral cable. Thats the cable that runs through the center of the wheel. Its wound sort of like a spring that winds and unwinds as the wheel turns. That way you can spin the wheel and have wires for the horn, cruise, lights, or whatever else. When it gets old it will start to crack when the wheel is in certain positions. Sounds like it from what you're describing.
(scratch head) Erm, I always thought hot lead went to the horn (the actual noise-making thing under the hood). The second terminal at the horn goes to the horn button which completes a ground. If one lead at the horn is hot, try grounding the other terminal and see whether the horn fires.
Unless Tercels are very different from every other car I've tinkered with...
That was it! I took off the steering wheel and noticed that the previous owner (my brother) had inserted washers behind the 3 screws holding on the copper horn ring. I replaced the screws with longer ones and inserted thick rubber rings to push the ring further away from the wheel. When I reinstalled the wheel, the voltage was 12 volts at all points.
Unfortunately, the horn is in bad shape ... it rattles more than honks. I've always wanted a loud semi-truck horn sound on a small car such as this Tercel. Now I have an excuse to replace the horn. :)
Thank you! It was my brother's 1st car that he bought when he was just out of college. He gave it to me at the turn of the year after not driving it for quite some time.
It had a few problems of which the Haynes manual helped me with. So far I've replaced rear wheel cylinders, rear shoes, rear drums, tie rods, and steering rack boots. Since the AC didn't work, I went on and removed the extra belt and air compressor (dead weight). I've still got a audible grinding sound when turning; I'm hoping it is only the wheel bearings.
Overall, it is a great car that gets 28-30 mpg. The only downside is that I have to run premium gas in it because the engine and carburetor have been tweaked for racing. Yeah, go on and laugh, but this car can fly.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.