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Horn not working anymore.

36K views 25 replies 11 participants last post by  macmanjimmy 
#1 ·
Yep.. I searched and did most of the troubleshooting already.

  • Horn does not work
  • Both horn and panic button won't set it off
  • Heard the clicking from the passenger side engine fuse box.
  • Swapped the horn fuse on the driver side engine fuse box, no change.
  • Checked both horns for corrosion, connectors are good.
  • Re-seat the integration relay, no change.

My deduction is that my integration relay is kaput. Since panic won't work, it can't be the cable reel can it?

Thanks!
 
#2 ·
Horn does not work
  • Checked both horns for corrosion, connectors are good.
My deduction is that my integration relay is kaput. Since panic won't work, it can't be the cable reel can it?
I don't know what you mean by cable reel, so I can't answer that question.

The most common cause of horn failure, are the horns themselves. Of course it's unlikely both would die at the same time, but if you're like me and only use the horn every few months, you would not have noticed when the first horn died.

Since you have already accessed the connectors on the horn, it would be a simple step to just remove the connector and connect the horn to the positive terminal of the battery (using a piece of wire). If the horn doesn't work with the jumper wire it might be a good idea to remove the horn and clean the mounting brackets to ensure you have a good clean ground point. You can eliminate this most probable cause in only a minute before speculating on more unlikely causes.
 
#3 ·
If you hear the clicking, then the integration relay must be working. Like Rick suggested, run a wire from the positive terminal of the battery to each horn connector. If they work, then check for voltage at the wiring where it plugs into the horns when the horn pad is pressed.
 
#4 ·
Just because the relay is clicking does not mean it is working. The click is caused when the coil is energized, and the contacts close.


You could be missing the power input at the relay, which is supplied by the horn fuse. I would get a test light on the horn connectors. I doubt both horns quit at the same time.


Looking at the schematic, it is a very simple circuit. At the horn relay you will have two power sources, both supplied by the 10A fuse in the engine room junction box marked HORN.


One power source is for the coil, and the other power source is for the horn relay contacts. When the horn pad is depressed, this supplies a ground for the coil. This causes the contacts to close.


Once the contacts are closed, power flows from the fuse, through the contacts to the horns provided there is power at the contact point and that the circuit from the relay to the horns is intact.


Try hot wiring each horn to verify that they work.


The clockspring in the steering column could be bad, but since you have nothing with the fob too, then I doubt that is the problem.

Looking at my information sources, this is not a common problem with the RAV4.


As a first step, verify with a test light that you have two positions in the relay connector that have power.
 

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#5 ·
Thanks all! I guess the bumper cover is coming off tomorrow. :)

As you all suggested I will have to test each horn.

@ FixIt, thanks for the picture - per your picture does it mean that I missed a 15A fuse at the "instrument panel j/b"? I am not good at reading electrical diagrams.. but it looks like even if there is a burnt out fuse @ the instrument panel j/b the panic alarm should still work?

Thanks,

Kenny
 
#7 ·
@ FixIt, thanks for the picture - per your picture does it mean that I missed a 15A fuse at the "instrument panel j/b"? I am not good at reading electrical diagrams.. but it looks like even if there is a burnt out fuse @ the instrument panel j/b the panic alarm should still work?

Thanks,

Kenny



That is not a 15 amp fuse. It is pin 15 at the Body Control Module. The BCM is what triggers the horns when the fob is pressed and if equipped, sounds the horns when the alarm is tripped. That is why it is teed off the signal side of the relay.




Before you pull the front bumper cover, check for the right voltages and signals at the horn relay. That is a lot easier. Unless something chewed through the wires, I would bet JuneBug's paycheck that both horns are not bad.




>:D
 
#8 ·
Good morning!

Woke up this morning and found that I forgot to close my rear windows and someone went thorough it and stole a few things. :(

Anyways.. I tried to test the relay. I got ~33k with 1A-8 - 1C-1, but I don't even have a wire at 1A-5.

I also don't know how to test "when battery voltage is applied to terminals 1A-7 and 1A-6"

Thanks,

Kenny
 
#9 ·
update 2:

I think I found the problem. I took off the bumper cover after the Police left. Using a voltmeter I found a few more things.

  • Tested the horn connectors and found they are live (~12v) when I hit the horn pad.
  • I then removed both horns and connect them directly to the battery. Both don't make a peep.

So I am now 99% sure it's caused by the horns. As Rick mentioned the one of them might have died a while back and the other one went tits up just now.

Ordered the El Grande from Amazon and they will be here tomorrow. I will post the final result.

Thanks all! You guys rock!
 
#15 ·
You must have been using only one horn for some time, then the other one quit.


Having both horns quit at the same time is like having your dishwasher and refrigerator both quit at the same time. Possible, but unlikely.
 
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