Horn problem on an '82 fj40

[taro]

Problem: when I hit the horn buttons, all I get is a clicking sound from both horns.


From what I can figure, there is no horn relay on late model fj40s. I took apart the steering wheel and the buttons and copper disc seem to be making good contact. I tested the horns to the battery and they work.


When I was putting the horns back on, I dropped one of the mounting bolts and cannot find it. So I only mounted one of the horns and it works when the engine is on, but does not when the engine is off.


So I'm guessing this is a current issue. At this stage, am I left with taking apart the wiring and checking it from the steering wheel to the horns? Any advice would be greatly appreciated!


Thanks, Taro

 

[Bambi Girl]

Hi
This must be a common problem as my 1982 suffers the same problem.
I'm in the middle of a chassis up rebuild so I won't get to the horn for a few. Months yet.
Will keep an eye on your thread to get ideas.
Cheers

 

[huminajumina]

So as far as I understand horns have power supplied to them and the steering wheel button just grounds out the horns to activate them. There are many posts on here about 1 horn not working because it is not getting enough current. I would start by using either a test light or a multimeter and check voltage, if you have resistance you will have a voltage drop. It sounds like what you said is right. With the engine on you have an increase in voltage to overcome any additional resistance due to corrosion. If you ring out the wires with the multimeter you will probably find a faulty connection/corrosion inhibiting the flow of electricity.

I would wire brush my slide on connections under the hood, and the mounting bolts, they are more likely to corrode then the steering wheel contacts. (I only brought up the mounting bolts if our horns are connected like mine, where the button provides 12VDC+ and the horns have a chassis ground through the mounting bolts)

 

[taro]

Bambi Girl, good luck with your build!

huminajumina, thanks for the input. The contacts at both the steering wheel and at the horns look good. I'll break out the multimeter and see what kind of numbers I'm looking at.

Thanks, Taro

 

[taro]

Okay, finally got the multimeter out..02V at the steering wheel and at the horns. Are there common areas where the wiring tends to have problems (rubbing, etc.)? Thanks, Taro

...via IH8MUD app

 

[bj40green]

Okay, finally got the multimeter out..02V at the steering wheel and at the horns. Are there common areas where the wiring tends to have problems (rubbing, etc.)? Thanks, Taro

...via IH8MUD app

You measured at the downside from the horn to the steering wheel contact.
It's more interesting to see how much the voltage drops on the + side of the horn when you hit the button.
Replace the fuse and clean contacts. Corrosion/bad contacts/old fuse is often the culprit.
If that doesn't solve the problem you have 2 ways to go:
1. Check the wiring from head to tail which can be a real PITA
or
2. Install a horn relay, feed direct from the battery and be amazed HOW LOUD these 30+ years horns sounds.

All you need is a horn relay and an in-line fuse. 20 minute job.



Or you can use a Bosch relay (#0332019203) with double output terminals


Rudi

 

[taro]

Rudi,

Thanks for the great info. The fuse and contacts are good. The horns are aftermarket that I bought at NAPA. I'm going to try to make a go of trying to find the problem in the easily accessible places and if not, add the relay. Thanks again! Taro

...via IH8MUD app



...via IH8MUD app

 

[456z]

taro,
Not sure if an 82 is the same as a 79 - what i'm used to. Had the same problem when putting mine back together . Mine problem was where the steering column meets the steering box (rubber joint) there is a jumper wire that allows ground from steering wheel to steering box. The wire was not the problem it was the rivets that feed the jumper wire.

With the steering wheel off or horn switch exposed see that you have 12v, if you do then take a jumper wire and ground(outside the steering column) the horn switch and if it honks then a bad ground past the horn switch is your problem . If you do not have 12v then find where you have lost supply voltage.
Mike

 

[Shark56]

taro,
Not sure if an 82 is the same as a 79 - what i'm used to. Had the same problem when putting mine back together . Mine problem was where the steering column meets the steering box (rubber joint) there is a jumper wire that allows ground from steering wheel to steering box. The wire was not the problem it was the rivets that feed the jumper wire.

With the steering wheel off or horn switch exposed see that you have 12v, if you do then take a jumper wire and ground(outside the steering column) the horn switch and if it honks then a bad ground past the horn switch is your problem . If you do not have 12v then find where you have lost supply voltage.
Mike

THIS! Make a jumper wire to jump the coupler.

 

[bikersmurf]

X2 on adding a relay.

Good 30 Amp headlight relays were $2.70 each the last time I bought some from the Local
Big Rig shop... Western Star Trucks for anyone who's got one local. I bought a few at the time because it'll cost me more than that in gas to get there.

 

[taro]

456z, thanks for the info, and Shark56, thanks for the input. I grounded the horn button and voltage went up to 2, but still no sound. So I guess, I'm still going to have to look into the wiring.

bikersmurf, thanks for the info. The horn relay is sounding better, but I'll feel better at least beginning to try to trace the problem.

Thanks, Taro

 

[456z]

taro,
After re-reading this thread i was wrong in suggesting a bad ground. You have to find where you are loosing your supply voltage. Start at the fuse holder not the fuse itself and see that you have 12v on both sides of the fuse. If you do then go to the horns and check. Last would be the horn switches.
While checking then fuse holders if you have 12v push the horn button to see that it maintains the 12v.
Mike

 

[taro]

456z, thanks for your thoughts. I'm out of town, but as soon as I get back home, I'll try to find the problem.

...via IH8MUD app

 

[jo 2f]

Problem: when I hit the horn buttons, all I get is a clicking sound from both horns.


From what I can figure, there is no horn relay on late model fj40s. I took apart the steering wheel and the buttons and copper disc seem to be making good contact. I tested the horns to the battery and they work.


When I was putting the horns back on, I dropped one of the mounting bolts and cannot find it. So I only mounted one of the horns and it works when the engine is on, but does not when the engine is off.


So I'm guessing this is a current issue. At this stage, am I left with taking apart the wiring and checking it from the steering wheel to the horns? Any advice would be greatly appreciated!


Thanks, Taro

same problem for my '81 fj40
just clicking sound...

 

[taro]

Okay, I've got 12+v at both ends of the fuse box. Just when I was getting ready to tear into the harness, I decided to check around the horn connections first. I'm glad I did because I found an old repair area that was not looking too good. I fixed it and now I have 12+v at the steering wheel, but it still just clicks.

I looked around at the base of the steering column/box and I do not see any type of wires at all. Nevertheless, I again grounded the steering wheel and I still only get clicking. I go from 12.48v to just under 2v.

Question 1: I am grounding the steering wheel with a 16 gauge wire. Is this thick enough?

Question 2: What else should I be looking at?

Thanks, Taro

 

[taro]

ps--jo 2f, welcome and best of luck with yours!

 

[bj40green]

Okay, I've got 12+v at both ends of the fuse box. Just when I was getting ready to tear into the harness, I decided to check around the horn connections first. I'm glad I did because I found an old repair area that was not looking too good. I fixed it and now I have 12+v at the steering wheel, but it still just clicks.

I looked around at the base of the steering column/box and I do not see any type of wires at all. Nevertheless, I again grounded the steering wheel and I still only get clicking. I go from 12.48v to just under 2v.

Question 1: I am grounding the steering wheel with a 16 gauge wire. Is this thick enough?

Question 2: What else should I be looking at?

Thanks, Taro

Let's go one step back. You say you hear a "click". Does that clearly come from the horns or does it come from under the hood on the fender?
If it comes from the horn you should feel it when you hold your fingers on the horn.
The reason I ask is that a bad functioning horn makes a "oink" or "plunk" sound.
A relay makes a "click" sound.

Rudi

 

[taro]

It's definitely coming from the horns. They work when directly connected to the battery. I looked for a relay before I realized the later models do not have one and in fact did not find one :-(

...via IH8MUD app

 

[bj40green]

Okay, so it's definitely from the horns and there is no relay.

Then this is the diagram.


Please tell me the voltages you see when you hit the horn.
I want them all three. Horn positive side, horn negative side and horn switch.

► Post these numbers first before you continue to do the test below. ◄
I can tell from the numbers what the problem is.


Test:
Take your jumper cables.
Use only the black one.
Hook one side up to ground or better the negative battery stud.

Hold the black jumper cable to the negative side (bottom in the picture) of the horn(s). Works now? YES = OK
NO = Bad power supply from fuse to horns.

Hold the black jumper cable to the wire on the horn switch on the steering wheel (you don't have to hit the button, just hold the cable to that wire).
Works? YES = wire from horns to switch is OK.
NO? Hold the black jumper cable to the ground side of the horn switch and hit the switch.
Works? YES = Switch is OK.
NO? Hold the black jumper cable to a metal surface on the steering wheel and hit the switch.
Works? YES = Switch to ground is OK
No? bad contact from switch to steering wheel or steering column.
Hold the black jumper cable to the steering column and hit the switch.
Works? YES = steering wheel makes good contact with steering column.
No? Steering column doesn't make good contact with frame/chassis/body.

You've reached the end of this test. By now you should have found the problem.

Rudi

 

[taro]

Rudi,

Thanks so much for your help! At the horns, the voltage drops to around 7v at one side of the horn and around 4v on the other side for both horns. At the horn buttons, it drops to around 2v. Thanks again, Taro

...via IH8MUD app