Hello All:

If the horn buttons on your high mileage PU have become intermittant, the problem is likely the sliding brush that contacts the circular brass ring behind the steering wheel. I thought my problem might be the contacts behind the buttoms, but the problem remained after r&r.

Unfortunately, the sliding brush is a part of the multi-function switch and is not available as a seperate part. Here's how I fixed mine:

1) From behind the steering wheel, remove the two lower phillips head screws holding the horn pad to the wheel.

2) Carefully pry the top of the pad loose (two plastic ears, so be gentle).

3) The short wire to the brass slider ring may come loose at this point. Otherwise, disconnect.

4) With the steering locked, remove the nut securing the steering wheel.

5) A wheel puller would come in handy at this point, but there are two threaded holes in the wheel base and with a bit of effort you may be able to put together a "poor mans wheel puller" like I did. Seems like it's going nowhere, then suddenly "pops".

6) On the back of the wheel is the brass ring I mentioned, attached by three small phillips screws. Remove.

7) Use the removed brass ring for a template and mark a pattern on a piece of thin cardboard...I used the light cardboard backing sheet from a pad of paper.

8) Cut out a washer shaped spacer from the traced template. Put this spacer under the brass ring to jack it up enough to compensate for the worn spring loaded brush. Reinstall.

9) While everything was apart, I made an opportunity to scuff up the three ears on the brass ring, where the screws attach it to the back of the steering wheel. Also, used some cleaner and lube on the brush/spring assembly to free it up. Finally, I scuffed up the surface of the brush itself.

10) Before reinstalling the wheel, pop out the "Toyota" center section of the steering pad. The "Toyota" pad has several ears (easy) and two plastic posts (tricky)...caution advised. Pulling this pad and reinstalling it last makes plugging the (very) short connector back into the tab on the brass ring. Mysteriously, I had to add a 2" section of wire to make the connection (??).

11) Finally, the two arms of the steering pad are a tight fit under the leather wrap on the steering wheel, so I used some silicone spray.

12) Reinstall the two phillips screws, test the horn*, pop in the "Toyota " center pad and enjoy blowing the horn, without wiggling the wheel .

Did I mention, my '87 has 315k miles?

The book recommends disconnecting the battery when working on electrics, but I've always felt this eliminates much of the excitement :-).

* By leaving the battery connected, you may have many opportunities to "test" the horn as the work progresses :-).

Usual disclaimers...YMMV

Finally, apologies for no pics, which would have condensed the above to 5 words (+/-).

 

My 83 is starting to do that, it hasn't been a big enough pain for me to fix it yet, but at some point I will need to!

 

Good write up, but your wrong about the sliding brush contact being available seperatly, it is available seperatly and the part number is 84312-20011.

 

it is a good write up . i had thought about doing it on my 89 ,but it doesn't have screws on the plate . my truck has plastic tabs holding the plate down. but is something to think about.

 

awesome and thanks to all for sharing the knowledge

 

I spent several hours taking apart and cleaning the contacts on my steering column before I realized the contacts were fine and the horn itself was bad.

So it might be a good idea to confirm that the horn itself works before diving into a project like this.

 

Another common issue (well, one that my truck had) was the CV joint in the steering shaft was really greasy and covered in dust and gunk.
The horn circuit grounds throw this CV joint. If it has a bad connections, the horn will be intermitten.
Spray the heck out of the CV joint with WD-40 or brake cleaner or anyother degreaser/cleaner.
A way easier way to get at the horn is to simply remove the horn cover (one screw) and the steering column shroud (3 or 4 screws).
If you upgraded your horn to something else. Check to make sure it has a good ground (i.e. sand down the paint).

 

Mine had the same problem, the little spring loaded plunger wasn't making contact with the horn ring. I took an empty 22 cartridge (already fired) and sawed about 1/8" or so off the rim end, making a little cap to extend the plunger length. It fit right over the plunger and the horn works for the first time in a long time.

Bob

 

Bob T beat me to it. I was going to suggest the 22 shell trick also.

 

That is a great solution, works fine, easy to do, thanks so much!

 

you don't need to cut the 22 shell. it works just fine as-is. i've had the mod installed for 3 years now, still works.

 

I just scuffed the whole shell with sandpaper and steel wool for better conductivity