Tercel Horn Problem

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.

Start with the easy stuff - see if you have battery voltage at the horn
plug under the hood when the button is pressed.

qslim wrote:[color=blue]
> Start with the easy stuff - see if you have battery voltage at the horn
> plug under the hood when the button is pressed.
>[/color]

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.

What's going on here?

"O.B." <funkjunk@bellsouth.net> wrote in message
news:gof_f.4236$Za3.1046@bignews7.bellsouth.net...[color=blue]
> qslim wrote:[color=green]
>> Start with the easy stuff - see if you have battery voltage at the horn
>> plug under the hood when the button is pressed.
>>[/color]
>
> 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.
>
> What's going on here?[/color]


Could be the contact on your horn button slip ring.. You may need to remove
the wheel to inspect/repair. Should be an easy fix.

I love your car, I had one, and I think it was FANTASTIC!! ;)

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.

qslim wrote:[color=blue]
>
> Start with the easy stuff - see if you have battery voltage at the horn
> plug under the hood when the button is pressed.[/color]

(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...
--
Mike Harris
Austin, TX
1995 Toyota Tacoma 2WD 2.4L
1987 Toyota Corolla Liftback FWD 4AF 1.6L DOHC
1963 4WD Willys Wagon SBC conversion
1984 Sovereign 17 "Gettin' Short" (Trailer Sailor)
List owner, Toy_Coma [url]http://autos.groups.yahoo.com/group/Toy_Coma/[/url]
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Home Page [url]http://www.geocities.com/harriswillys/harriswillys.html[/url]
Founder, TNWPS (Texas Nuclear Weapons Preservation Society)
WTB: 1958 Ford Nucleon, any condition. Cash/Trade.

Robert Gilroy wrote:[color=blue]
> "O.B." <funkjunk@bellsouth.net> wrote in message
> news:gof_f.4236$Za3.1046@bignews7.bellsouth.net...
>[color=green]
>>qslim wrote:
>>[color=darkred]
>>>Start with the easy stuff - see if you have battery voltage at the horn
>>>plug under the hood when the button is pressed.
>>>[/color]
>>
>>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.
>>
>>What's going on here?[/color]
>
>
>
> Could be the contact on your horn button slip ring.. You may need to remove
> the wheel to inspect/repair. Should be an easy fix.[/color]

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. :)
[color=blue]
> I love your car, I had one, and I think it was FANTASTIC!! ;)[/color]

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.