Deep_palancar
New member
Good additional info. Will be useful in determining which side of the horn relay the problem is on.
I've edited my original post to reflect this new knowledge.
Car horn not working
- Thread starter kiyeoul
- Start date
Good additional info. Will be useful in determining which side of the horn relay the problem is on.
I've edited my original post to reflect this new knowledge.
Pathfinder!
New member
Sounds like someone forgot to change their horn fluid. Didn't you even read the manual? :der:
HI [MENTION=3606]Deep_palancar[/MENTION]
I have had the time to test the circuit today. First I wanted to confirm there was a third horn for the alarm and indeed there is.
I disconnected the street horns and press the panic button. The alarm horn was loud and clear.
Next I removed the street horns and cleaned the contacts and tried again. Nothing.
I have tried the original horn without any more success.
The cable is not damaged as far as I can follow it. There is not much to see though as it soon enters a cable protector that runs hidden within a narrow channel of the frame above the radiator and then it's visible again until the fuse box.
I removed the extended wire the previous owner added to connect the Flamm horns and got some help to verify if there was any voltage at the end of the original cable. My gf pressed the horn and my multimeter showed +12.66V which is the same voltage I have measured at the battery poles.
I guess I have to test the integrated relay?
How can the horns not work when the circuit is closed since I am reading +12V?
Thanks,
Sylvain
I have had the time to test the circuit today. First I wanted to confirm there was a third horn for the alarm and indeed there is.
I disconnected the street horns and press the panic button. The alarm horn was loud and clear.Next I removed the street horns and cleaned the contacts and tried again. Nothing.
I have tried the original horn without any more success.
The cable is not damaged as far as I can follow it. There is not much to see though as it soon enters a cable protector that runs hidden within a narrow channel of the frame above the radiator and then it's visible again until the fuse box.
I removed the extended wire the previous owner added to connect the Flamm horns and got some help to verify if there was any voltage at the end of the original cable. My gf pressed the horn and my multimeter showed +12.66V which is the same voltage I have measured at the battery poles.
I guess I have to test the integrated relay?
How can the horns not work when the circuit is closed since I am reading +12V?
Thanks,
Sylvain
bnorton00
New member
12V is not necessarily a true test of a “closed” switch. When you measure the voltage of a circuit, you are actually measuring the amount of voltage dropped by resistive components in the circuit. If you are measuring across one component, Ohm’s Law will apply. If you are measuring ALL the components of a circuit together, you should end up with source voltage.
My recommendation would be to see if you have current in the circuit of your closed switch. That will provide some valuable insight to the problem at hand.
An easy troubleshoot I used for wire diagnostics:
Current/No Voltage = Closed circuit, no resistance (Potential short to ground)
No Current/Source Voltage = Line Break or Open Switch
Current/Voltage = Normal circuit. Check Ohm’s Law values against schematics.
My recommendation would be to see if you have current in the circuit of your closed switch. That will provide some valuable insight to the problem at hand.
An easy troubleshoot I used for wire diagnostics:
Current/No Voltage = Closed circuit, no resistance (Potential short to ground)
No Current/Source Voltage = Line Break or Open Switch
Current/Voltage = Normal circuit. Check Ohm’s Law values against schematics.
Street horns? Like the normal horn that is OEM? Flamm horns?
It's a pretty simple circuit. At the OEM horn, green/red should have power when the relay energizes by hitting the horn on the wheel. You also have ground, which the OEM horn should be securely bolted down. 12v and ground is all that is needed to make the OEM horn go off.
It's a pretty simple circuit. At the OEM horn, green/red should have power when the relay energizes by hitting the horn on the wheel. You also have ground, which the OEM horn should be securely bolted down. 12v and ground is all that is needed to make the OEM horn go off.
Deep_palancar
New member
If you have +12v at the wire end then the only thing needed is a ground and a good horn.
Some horns have two posts, one for + and one for -(ground), some have only one post for +12v and are grounded via the mounting post.
Test the horn with direct connections + and ground to the battery.
If they work then clean the ground connection; either wire or post to ensure good metal to metal contact.
Hi,
I will check the direct connections later this week. The original horn has only one male post while the Fiamm horns have two. But it was connected with only one cable while being attached to the frame and this was working. They look like this:
http://www.toyota-4runner.org/5th-gen-t4rs/59265-new-fiamm-horn-install.html
And that's basically the mod that the previous owner did.
Thank you again for the help.
Sylvain
I have checked the OEM horn today. It was removed from the truck so not grounded at first.
I ran two wires, (+) and ground, from the battery terminals directly to the horn. It worked.
Then I re-attached the horn to the truck in its original spot so it was grounded.
I ran a wire from the positive terminal of the battery to the horn only connector and it worked.
I then connected the original wire with female connector to the horn and pressed on the horn pad. Nothing.
So the issue appears to be between the fuse box where the relay is located and the horn itself.
What would be the next step?
Thanks,
Sylvain
I ran two wires, (+) and ground, from the battery terminals directly to the horn. It worked.
Then I re-attached the horn to the truck in its original spot so it was grounded.
I ran a wire from the positive terminal of the battery to the horn only connector and it worked.
I then connected the original wire with female connector to the horn and pressed on the horn pad. Nothing.
So the issue appears to be between the fuse box where the relay is located and the horn itself.
What would be the next step?
Thanks,
Sylvain
rigtec
New member
...did you say that the Horn relay is clicking when the horn pad is pressed? That does NOT mean that the relay is good; could have bad load feeding contacts. But if it clicks, that just means that the primary circuit from the horn-pad is working, which activates the relay coil... first-things-first!
rig, cheers
Deep_palancar
New member
It's looking more and more like a bad integration relay. One final check that I would do before purchasing a $130ish part is to check the whole wire from the relay to the horn.
I pulled my integration relay and found that the connectors and wire bundles come out of the box far enough to easily probe the back of the connector. (I was expecting the connectors to be affixed to bottom of the fuse box and difficult to access.)
Pull the integration relay up and out of the fuse box.
Stick the back of connector 1C pin 8 (Grn/Red) with a wire or your multimeter probe. touch the other end to the battery +. If the horn does not sound, run a new wire. If the horn sounds, replace the integration relay.
This part is plasti-welded closed so opening it up to try to replace just the actual component would be risky. There is circuitry in there that controls the fuel injection and ignition so a screw-up would leave you parked until you could get a new one.
FWIW, you stated earlier that you did get +12v at the horn wire; It's possible to get a good voltage read when there is no load on the circuit (it only takes a little current for the meter to register) but there is not enough current to activate the device. This would be a classic symptom of bad contacts in the relay.
Curiosity questions.. What size fuse is the horn slot? Were all four horns originally connected?
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Deep_palancar
New member
Correct. It's the box with the 4 fuses on top. "K" is printed on one end.
mountainair26
New member
I find the stock horn on my 2010 tfr to be a bit weak, as others have mentioned. I'm thinking of installing the hella dual disc horn set, since the stock horn only has one disc and it sounds like an old camry. If I go with the hellas, is there a major difference between the 77mm and the 92mm other than size?
mountainair26
New member
If adding aftermarket horns like the simple hella disc models, is adding a relay essential to get the full benefit? I'm looking for a little bit stronger horn, but not the blow people away in cross walks.
Horn problem
I have a similar problem with my 2012 4Runner. I took it to my local auto shop and they said it looked like the P/I-B 80 amp fuse was causing the problem. He also said he was not able to get that particular fuse. Anyone have any ideas what something like this can cost and would I have to purchase it from a dealership. Thanks
I have a similar problem with my 2012 4Runner. I took it to my local auto shop and they said it looked like the P/I-B 80 amp fuse was causing the problem. He also said he was not able to get that particular fuse. Anyone have any ideas what something like this can cost and would I have to purchase it from a dealership. Thanks
Horn and Steering Wheel Controls - A/C Breaker
So my 2012 horn and steering wheel controls lost all power. Nothing worked. I did not believe it was the clockspring so started testing all fuses and breakers. FOR NO LOGICAL REASON the A/C Compressor breaker serves the power to the steering wheel.
Would have figured it out this summer but glad it's resolved.
I hope this helps anyone else having the issue. Check this breaker before you go and replace your clocksprings.
So my 2012 horn and steering wheel controls lost all power. Nothing worked. I did not believe it was the clockspring so started testing all fuses and breakers. FOR NO LOGICAL REASON the A/C Compressor breaker serves the power to the steering wheel.
Would have figured it out this summer but glad it's resolved.
I hope this helps anyone else having the issue. Check this breaker before you go and replace your clocksprings.
Hi,
As far as mine is concerned publicly stating the solution is a bit embarrassing. As part of my 240 000km (150 000miles) Toyota check up at the dealership I asked them to check the horn. They cleaned the contacts as they were corroded. I had done the male part but not the female one. Duh. The OEM horn has been working fine since then. I have yet to try the Fiam ones again though.
Hey guys, I'm also having an issue with the horn in my 2012 Limited, and I'm thinking it's the clock spring, here's the troubleshooting I've done:
-Checked horn fuse in K unit, is good. Swapped just in case, still no horn
-Pulled S-Horn relay and set off car alarm, horn honks, implies to me the horns themselves are fine, and the horn relay in the K unit is good.
-When I press the horn pad, nothing happens. No clicks no nothing. Implies the signal from the horn pad to the relay isn't getting there.
-I pulled the horn pad, and identified the two airbag wires and the horn wire. My understanding is the horn lead is connected to the whole back of the horn pad, and when you press the pad it touches the wheel which is grounded. This completes the circuit and triggers the horn relay. If I touch the wire to the steering wheel, nothing happens, and there's zero voltage from the wire to the column. I even unplugged the connector from the clockspring and checked voltage from the pin in the connector to the steering column, no voltage.
At this point I'm thinking it has to either be the clockspring or the connection from it to the relay in the fusebox, but I'm not sure how to find test points to verify continuity there, and honestly the clockspring seems WAY more likely than a static wire that's never been touched or moved in the last 8 years.
Thoughts?
EDIT: side note... do your horns work when the truck is totally off? Or do you need the ignition in the "on" position? I tried both ways but I just wanted to know for future testing.
-Checked horn fuse in K unit, is good. Swapped just in case, still no horn
-Pulled S-Horn relay and set off car alarm, horn honks, implies to me the horns themselves are fine, and the horn relay in the K unit is good.
-When I press the horn pad, nothing happens. No clicks no nothing. Implies the signal from the horn pad to the relay isn't getting there.
-I pulled the horn pad, and identified the two airbag wires and the horn wire. My understanding is the horn lead is connected to the whole back of the horn pad, and when you press the pad it touches the wheel which is grounded. This completes the circuit and triggers the horn relay. If I touch the wire to the steering wheel, nothing happens, and there's zero voltage from the wire to the column. I even unplugged the connector from the clockspring and checked voltage from the pin in the connector to the steering column, no voltage.
At this point I'm thinking it has to either be the clockspring or the connection from it to the relay in the fusebox, but I'm not sure how to find test points to verify continuity there, and honestly the clockspring seems WAY more likely than a static wire that's never been touched or moved in the last 8 years.
Thoughts?
EDIT: side note... do your horns work when the truck is totally off? Or do you need the ignition in the "on" position? I tried both ways but I just wanted to know for future testing.
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