Car horn not working
- Thread starter kiyeoul
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not gonna lie but don't even know what that is... :shrug::redface:
rigtec
New member
Hi kiyeoul,
It seems as if you've lost the ground source; which in this case is at the steering wheel position... "See the diagram below":
The fact that the horn works when you hit the panic feature on the key fob tells us a lot! When you hit the horn button on the SW, you're just grounding that circuit... but it doesn't work now when you hit the horn button. BUT... it does work when you use the alarm; which provides a ground from the Main Body ECU. The power source is one and the same, including the fuse and horn relay. So try removing the SW pad and look for the horn button. Now try grounding the switch using a piece of wire that'll reach a good ground; perhaps the metal cigarette lighter housing (the cylindrical part that a lighter or phone charger would slide into).
The horn should blow! If not, listen for a clicking from under the hood; here is your horn relay with the RED ARROW below:
That relay should be clicking each time you connect your ground wire to the switch terminal and ground source! If it works you've lost the ground (the switch is likely N/G!) However: be sure to check for a loose or broken wire or the 'Spiral Cable' in that horn assembly before you replace the switch, and let us know how you're making out so that we can follow through with this electrical investigation! 'Best to you'!
rig
Hi,
I have exactly the same issue on a 2010 TE so I am replying in this thread if it's allowed. The horn stopped working after I hit the horn pad out of frustration and it has not worked since then. When I did hit the horn pad it triggered the BT phone connection so I hit near the edge of the pad.
However when hitting the alarm button on the key fob the norn does what it should do and is loud. Also all other functions on the steering wheel are working (BT, cruise control, radio controls).
I have tried changing the fuse without success.
When I press the horn pad on the steering wheel I can hear a relay clicking. So that relay works.
Am I understanding correctly that it's lost the ground so, as [MENTION=83083]rigtec[/MENTION] suggested, the switch is not grounded?
If that is correct how can this be confirmed and fixed?
It's been nearly two months now without a horn and it's really annoying in many situations.
As a side note I have tried changing the spiral cable for one found on eBay. It did not work at all so I have been refunded. I am adding this to say that I can remove the steering wheel if needs be. However I am less familiar with working under the hood.
Thanks,
Sylvain
I have exactly the same issue on a 2010 TE so I am replying in this thread if it's allowed. The horn stopped working after I hit the horn pad out of frustration and it has not worked since then. When I did hit the horn pad it triggered the BT phone connection so I hit near the edge of the pad.
However when hitting the alarm button on the key fob the norn does what it should do and is loud. Also all other functions on the steering wheel are working (BT, cruise control, radio controls).
I have tried changing the fuse without success.
When I press the horn pad on the steering wheel I can hear a relay clicking. So that relay works.
Am I understanding correctly that it's lost the ground so, as [MENTION=83083]rigtec[/MENTION] suggested, the switch is not grounded?
If that is correct how can this be confirmed and fixed?
It's been nearly two months now without a horn and it's really annoying in many situations.
As a side note I have tried changing the spiral cable for one found on eBay. It did not work at all so I have been refunded. I am adding this to say that I can remove the steering wheel if needs be. However I am less familiar with working under the hood.
Thanks,
Sylvain
rigtec
New member
Hi smoisan,
...there's something you said that is contrary to your original statement that I'd like very much to clear up. Your original statement was that when you press the horn pad, you're getting NO HORN at all.
I know you've done what you can to remedy the problem by changing out the Spiral cable and that didn't work so you returned it for a refund; that's good! But what has me baffled is what you say next:
If you had NO GND at the steering pad, you'd have no horn relay operation; which triggers the horn sounders: please refer to the wiring diagram for verification! Okay, so we know (by your hearing the horn Rly clicking) that the primary circuit is in fact working!
What we do next is to get a test light ($5 bucks at Auto Zone) or you can use a multi-meter set to DC voltage if you've got one. Connect your testing device to the POS connector on one of the horn sounders (just behind the front grill) and connect the black test lead to any good GND; the NEG battery term will be best! Now Have someone press the horn pad on the sw.
You should see the test light/multi-meter showing 12V or the test light glowing brightly!. If not, pull the NEG wire off of the horn, connect the BLK lead to the ground wire (that you pulled from the horn sounder) and the other end of the test device to the POS battery post to see if the ground is any good at the horn.
If the ground proves to be good, (it shouldn't) reconnect it to the horn and check it again; It's gotta be one or the other at this point! If POS and the NEG both prove good, post that back here and one of us (or myself) will chime in the do further analytics!
rig, Cheers!
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The relay is activated so the circuit is closed by pressing the horn pad. So I don't think it's the spiral cable.
As an aside, I nevertheless went this route to being with as I mentionned. I purchased a spiral cable off eBay and it did not work at all. No bluetooth, no radio control and no cruise control. And still no horn. The part is poorly manufactured and tolerances are way off. I had trouble connecting back all cables. For example the female connector on the eBay spiral cable was smaller (and tighter) than the original male cable from Toyota. So I never could enter the cable far enough for it to "click".
rigtec
New member
Okay Sylvain,
As I stated in an earlier post, the steering wheel horn pad provides the ground source for the horn rly to Close the horn circuit; that IS happening, so whatever the trouble is, it's down stream of the horn relay.
Our Gen-5 4Runners operate on a Negative-side switching circuit! Older vehicles e.g., 70's, 80's, and 90's...etc worked on a POS-side switching circuit; which would switch the power on and off to feed accessories, and the accessories were ALL grounded, but that's a thing of the past!
When you find the time, just pull the horn sounder (horn module in front of the grill) POS wire (Green/Red) off of it's terminal; the NEG ground has no wire but rather, it's mounting bolt/casing provides it's ground! Energize the POS terminal from the battery pos terminal post; the horn should beep!
If it doesn't, remove it from the body, place it on the NEG battery post and energize the POS terminal again... it should beep. If it still doesn't, the horn is n/g! If it does beep, there is a BAD ground at it's mounting position e.g., rusty washer/bolt or surface area! Let us know!
rig, Cheers!
ElectroBoy
Banned
Didn’t smoisan indicate that the horn *does* work when he presses the panic button on his remote? If so, then the relay is OK. The clicking he hears is probably the mechanical action of the switch, but it lost an electrical connection.
The problem is probably at the actual switch under the horn pad, that got damaged when he banged on it. Or the spiral cable.
Check out thread entry 5 again.
The problem is probably at the actual switch under the horn pad, that got damaged when he banged on it. Or the spiral cable.
Check out thread entry 5 again.
[MENTION=200736]ElectroBoy[/MENTION] I don't know if it changes anything but the clicking I hear comes from the relay in the fuse and relay box.
ElectroBoy
Banned
Still, if your remote’s panic button operates the horn, the relay is good.
Maybe you have an intermittent damaged section on the spiral coil. You can try turning the steering wheel a couple of turns in either direction, trying the horn pad in various positions. If it works anywhere that points to the spiral coil.
I would only go with an OEM replacement if that’s the case.
BTW, how did you remove the steering wheel to do your try of the Ebay spiral coil? What kind of airbag precautions?
I did read a bit before removing the steering wheel and spiral cable.
I disconnected the battery and waited at least 20min before removing the air bag connectors.
I used a box to remove the steering wheel center nut and wiggle it out without pulling that hard.
I have tried honking with the steering wheel in different orientation without success.
Before purchasing the Toyota spiral cable for many hundred of dollars I would like to go through as many options as possible.
The spiral cable did not work since the replacement part seemed to had bad quality control. On the other hand others have purchased one from eBay and claimed it worked.
I have read another thread where it turned out the issue was fixed by replacing the main ECU.
Sylvain
ElectroBoy
Banned
For this problem the only thing in the ECU that would effect it is the internal connection from D29 to D25 being open. However that seems unlikely.
If you can get the steering wheel off and access the connectors, do some continuity checking with a multimeter (set to resistance, ohms) referenced to chassis ground per the diagram. Disconnect the Z9 connector from the horn switch. Connect a test lead to the output of the horn switch. Other test lead to chassis. Push the horn pad and see if you get a 0 ohm reading at the output of the horn switch. If instead you read open or a high resistance value: tens or hundreds of ohms, that’s your culprit.
If you do get 0 ohms when the horn pad is pushed , the switch is OK. Next reconnect Z9, disconnect Z11 from the spiral coil. Test Z11 pin 1 in a like manner. Reconnect Z11. Disconnect connector F23 from the spiral coil and test the coil’s output pin the same way. If you do not read near 0 ohms the coil is bad.
If you can get the steering wheel off and access the connectors, do some continuity checking with a multimeter (set to resistance, ohms) referenced to chassis ground per the diagram. Disconnect the Z9 connector from the horn switch. Connect a test lead to the output of the horn switch. Other test lead to chassis. Push the horn pad and see if you get a 0 ohm reading at the output of the horn switch. If instead you read open or a high resistance value: tens or hundreds of ohms, that’s your culprit.
If you do get 0 ohms when the horn pad is pushed , the switch is OK. Next reconnect Z9, disconnect Z11 from the spiral coil. Test Z11 pin 1 in a like manner. Reconnect Z11. Disconnect connector F23 from the spiral coil and test the coil’s output pin the same way. If you do not read near 0 ohms the coil is bad.
Deep_palancar
New member
Lets clear up some incorrect assumptions and information.
There are 3 horns on the truck. The S-horn is located on the right fender behind the air filter box. It is associated with the security system, has it's own "s-horn" relay, and is powered through the security fuse. The road horns (2) are behind the front grill, are powered through the "horn" fuse and the "horn" relay. Two different circuits.
The sounding of the security horn on lock/unlock (if enabled) <del>or panic button on the fob</del> is NOT an indication of the condition of the "horn" circuit. That event is all on the "s-horn" circuit.
The road horns fuse and relay are located on/in the "integrated relay" also referred to as 'Unit K' in the manuals. This module is in a slot at the rear of the fuse/relay box.
Top view:
Inner map:
Looks like this:
--------------------------
--------------------------
Since smoisan says that the relay can be heard clicking when the steering pad is pressed then the button, spiral coil, and all ecu connections up to the relay are good and the circuit is complete up to the integrated relay.
I would start at the horns with really basic checks. Does the wire connected at the horn look good as far back as you can visually trace it? Is there +12v at the connection with the horn when the steering wheel pad is pressed? If the wires look good and there is no power then it's either hidden wire damage or the integrated relay is suspect.
The integrated relay can be bench tested and tested in place. I can give you the procedure for that if needed. But first do the really basic checks.
Might be as simple as a critter damaged wire behind the grill.
There are 3 horns on the truck. The S-horn is located on the right fender behind the air filter box. It is associated with the security system, has it's own "s-horn" relay, and is powered through the security fuse. The road horns (2) are behind the front grill, are powered through the "horn" fuse and the "horn" relay. Two different circuits.
The sounding of the security horn on lock/unlock (if enabled) <del>or panic button on the fob</del> is NOT an indication of the condition of the "horn" circuit. That event is all on the "s-horn" circuit.
The road horns fuse and relay are located on/in the "integrated relay" also referred to as 'Unit K' in the manuals. This module is in a slot at the rear of the fuse/relay box.
Top view:
Inner map:
Looks like this:
--------------------------
--------------------------
Since smoisan says that the relay can be heard clicking when the steering pad is pressed then the button, spiral coil, and all ecu connections up to the relay are good and the circuit is complete up to the integrated relay.
I would start at the horns with really basic checks. Does the wire connected at the horn look good as far back as you can visually trace it? Is there +12v at the connection with the horn when the steering wheel pad is pressed? If the wires look good and there is no power then it's either hidden wire damage or the integrated relay is suspect.
The integrated relay can be bench tested and tested in place. I can give you the procedure for that if needed. But first do the really basic checks.
Might be as simple as a critter damaged wire behind the grill.
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ElectroBoy
Banned
That's what we get from referring to incomplete diagrams and not verifying our assumptions.
You are correct, sir. Nice research. :hatsoff:
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Thank you very much for the detailed write-up.
The first thing I did when the horn stopped working was to remove the wire leading up to it and connect the old one. I have Flamm horns but the old horns are still behind the grill. The old ones did not work either.
I will try to see how far I can follow the wire.
Sylvain
The main horns do go off with panic or the OEM alarm is triggered. The S-horn is for confirmation chirps with lock/unlock.
