horn button wire?

[fcgadget]

OK, if one side of the horn button goes to ground, the other comes out at the horn relay (Green/Red).

With a continuity tester the Green/white to horns shows connection.
with Voltmeter the Green/yellow shows 12+ volts

But when I meter the G/R wire to ground with the horn button pushed I get nothing. Open circuit. No continuity to ground.

But the horn does work when the connection is made.

What am I missing????

 

[bikersmurf]

The horn relay uses a ground trigger. The "coil" part of it has 12v+ at all times... When the other side is grounded, the relay is turned on, and the 12v input is then connected to the + side of the horn, completing the circuit.

 

[DonkyFly40]

Check the ground ring on the steering column. I had similar issues and that's where my problem was. It was not making contact with the ring when horn buttons were pushed.

 

[shelfboy1]

there are brushes inside the column actully only one but they wear out over the years

 

[antFJ]

i was able to buy a FJ60 horn brush for my 1971... I had to trim the brush down a bit to fit but it works just fine (for now)

 

[fcgadget]

The horn relay uses a ground trigger. The "coil" part of it has 12v+ at all times... When the other side is grounded, the relay is turned on, and the 12v input is then connected to the + side of the horn, completing the circuit.

I know about the horn ring connection inside the steering wheel, I've worked on it repeatedly. My problem is that when everything IS connected the horn works just fine.

But when I pull the horn relay plug off of the relay, connect a circuit tester to the wire coming from the horn to a ground and THEN press the horn 'buttons on the wheel there is no connection. It seems there should be a connection through the horn buttons/relay connection to ground, but there is none. Using an ohmmeter or circuit tester nothing shows aground connection.

 

[fcgadget]

I know about the horn ring connection inside the steering wheel, I've worked on it repeatedly. My problem is that when everything IS connected the horn works just fine.

But when I pull the horn relay plug off of the relay, connect a circuit tester to the wire coming from the horn to a ground and THEN press the horn 'buttons on the wheel there is no connection. It seems there should be a connection through the horn buttons/relay connection to ground, but there is none. Using an ohmmeter or circuit tester nothing shows aground connection.

I'mgoing to replace the old dual horns with a large, loud one from an old vehicle. I need to change the wiring for it to a larger gauge. Simple, but I ran into this connection question when I started the project. Again everything works, I just can't wrap my brain around the apparent lack of connection between the horn button toground (when pressed) and the relay connection of that wire to a ground as measured by a tester.

 

[bikersmurf]

The horn button wiring will be fine. Replace the horn relay with a 30 amp headlight relay, upgrade the wiring to & from the relay between the battery and horn.

 

[kruisinkid]

i was able to buy a FJ60 horn brush for my 1971... I had to trim the brush down a bit to fit but it works just fine (for now)

did you buy it new OEM? i have intermittant issues with the ring/sprung brass contacts i hope to fix

 

[antFJ]

did you buy it new OEM? i have intermittant issues with the ring/sprung brass contacts i hope to fix

yes FJ60 is still available

 

[DSRTRDR]

i was able to buy a FJ60 horn brush for my 1971... I had to trim the brush down a bit to fit but it works just fine (for now)

Tools R Us just fabricated one for me from a brass rod

 

[DSRTRDR]

the original poster did not say what year truck - but the insulation for the horn contact plate is important in an early model steering wheel horn button - you can use a large thin rubber washer from the hardware store to replace that brittle >40-year-old button insulator

take a pic to show us what you have

 

[sggoat]

I know about the horn ring connection inside the steering wheel, I've worked on it repeatedly. My problem is that when everything IS connected the horn works just fine.

But when I pull the horn relay plug off of the relay, connect a circuit tester to the wire coming from the horn to a ground and THEN press the horn 'buttons on the wheel there is no connection. It seems there should be a connection through the horn buttons/relay connection to ground, but there is none. Using an ohmmeter or circuit tester nothing shows aground connection.

Not sure of the question here. When everything is connected properly , it works. Why try to fix something that isn't broke? Are you just curious about learning how the circuit works?--I think there was a post some time ago(maybe LostMarbles/Coolerman/BJ40Green?) that gave a good explanation of this circuit--I can't remember who or when exactly, but --'Search is your Friend', as they say--

 

[bj40green]

Here is a quick draw of a 3 wire horn relay

Here is an upgrade to a 30Amp Bosch relay with double output tabs. You have to upgrade the fuse of course.

Rudi

 

[fcgadget]

I know, if it ain't broke......but I just can't figure out why if I meter the connection above at "s" right at the horn relay, why don't I get a 'short' to ground when the horn button is pushed?

 

[Coolerman]

I totally understand your dilemma! Here is a link to my issue when I was first working on my FJ40: http://www.globalsoftware-inc.com/coolerman/fj40/8.htm

What many fail to see when working on the horn is this: The steering column SHAFT is what MUST be grounded for the horn to work reliably since the button is attached to the shaft. Grounding the column shell may not work if there is no bearing in the end that is attached to the shaft. Also, if you have a rag joint, and don't have the correct jumper wire installed, you will have issues. On the early trucks with the shaft being part of the steering box, grounding was not an issue.

When you press the horn button which is attached to the shaft, which is grounded, you are grounding the isolated GR wire going to the horn S contact.

Now why are you having trouble measuring this? My question is what exactly are you using to measure this, and where are you actually measuring?

An ohm meter set to it's lowest setting should be used. If everything is connected properly you should measure under 10 ohms again depending on the condition of the horn "brush", the contact ring and the connection to the S terminal on the horn relay. If using a meter with a continuity setting the meter will beep if the ohms are under 200 ohms or so depending on the meter.

Sorry for the long winded response...

 

[Boaf 32]

LCer's,

I am running into a horn blowing issue. Originally, I had a huge wiring thread for the horn to get it to work. The insulator that inserts into the steering column has perished to a point that the top of the contact ring that the horn button uses to complete the ground circuit is touching the steering column. And beep away!

I have not seen replacement insulator part for this so wondering if anyone else has run into this.

My solution is drill a hole in the bottom of the Steering column and insert a screw to position the rubber a bit higher and not contact the Steering column. Another thought is somehow put a rubber washer around the top of the steering column to prevent contact.

Has anyone else run into this and what was your solution?

Thanks.

Bob

 

[Coolerman]

You could try wrapping the remains of your rubber insulator with electrical tape until it once again has a tight fit into your steering column, but that would be a temporary fix.

Seeing that the original rubber bushing had a lip on it to isolate it from the column, you could take it to a machine shop and have them machine a delrin or nylon equivalent to the rubber. You would need to take your column and the insulator to them of course so they could do it correctly.

 

[Boaf 32]

You could try wrapping the remains of your rubber insulator with electrical tape until it once again has a tight fit into your steering column, but that would be a temporary fix.

Seeing that the original rubber bushing had a lip on it to isolate it from the column, you could take it to a machine shop and have them machine a delrin or nylon equivalent to the rubber. You would need to take your column and the insulator to them of course so they could do it correctly.

And I thank you Coolerman. Tape first, and I have a rubber cap off of a Brake Caliper that I can try.

Cheers,

Boaf