Horn on constantly...help (1 Viewer)

[Placemotorsports]

I did a search but have not found an answer to my problem. The horn is staying on constantly. I have the relay pulled currently but with it in, I have constant voltage to the wires hooked to the horn. As soon as I plug in the relay I can feel it engage (click). I pulled the air bag out last night to see if any metal was touching but didn't see anything. I even left it resting out against a piece of rubber and checked the horn wire and still have constant voltage. Any ideas??

 

[bamabrock]

could be the door locks not fully functioning and activating the alarm.

 

[Placemotorsports]

Locks seem to be working fine. Even with the key in the switch it still has constant power. I would think if it were alarm related, the ignition switch being on would defeat that.

 

[Placemotorsports]

Hoping it stops raining soon so I can dig into it more. Anyone?

 

[Placemotorsports]

Finally getting a little time to mess with it. I have constant voltage to the terminal below the relay on one leg and of course voltage across both sides of the fuse. Took the air bag back out and looked around but don't see anything. What am i missing here that is giving me constant voltage?

 

[bjarnep]

Please find schematic for horn.
Of cause the 12V is present when the horn sounds constant. You have to check the horn contact connection that provides the negative/ground to the relay (might be as simple as the relay are faulty?) Now you dont inform the model year, so this schematic is for a 2004.
If the horn only sounds when the key is on. Then some models have the horn connected to theft alarm - could this be your problem?

 

[Placemotorsports]

I have a 2000. Power to the horn and relay are all the time regardless if the key is on or off. I pulled the relay out and have constant voltage to one leg on the terminal below it. I can unplug the wire going to the air bag portion of the wheel and I still have constant power.

 

[bjarnep]

Yes, - like I wrote above. there is a constant 12Volt to relay. There has to be/should be!! If the horn sounds with or without the key in, then the wire from relay (marked 21) is somewhere shorted to ground. OR the relay is defective.

 

[Placemotorsports]

So I need to unhook the fuse block and check behind it for the wiring I suppose to see which color it is and trace it back I suppose?

 

[bjarnep]

have you checked the relay?

 

[Placemotorsports]

Haven't tested the relay with a meter yet. I was under the assumption that if I had voltage across the 10a fuse and at a leg of the relay then the problem was beforehand.

 

[Ali FJ80]

If its been raining a lot you could have water seeping in and getting into the junction box in the driver side kick panel. Are you also having issues with your fog lights also by chance?

Take off your driver side A pillar and check for evidence of water entry (just remove the two bolts holding on the grab handle and the panel just pulls off). I would have either the constant horn on or fog lights on or both on and checked the stalks, airbag, clock spring, relay etc. I eventually took off the A pillar cover and found that water was leaking in around the windshield and making its way down into the junction box/fuse box and there are quite a few relays behind the fuse box that were probably getting wet. I sealed up where the water was entering from and dried out the area using a blower and left it parked outside in the sun with the kick panel removed to let it all dry and everything went back to normal.

 

[Placemotorsports]

It has been raining for over a week, yesterday was the first day it didn't rain. Haven't checked that is on my to do list now. Of course it is raining again now.

 

[bjarnep]

Cable colors are as follows: G O = Green/orange - SB = Sky Blue
Having 12 Volt on both sides of fuse and 12Volt on one leg of the relay is like it should be. The fault is either relay or short Circuit.

After taking out the relay, measure if there is 12Volt between 1 and 2 (on the schematic) If you cannot measure 12 Volt, you have a problem with the relay, if you can measure 12 Volt - then the problem is between relay and horn contact.

 

[Placemotorsports]

I have 12v only on leg 1 on the relay

 

[bjarnep]

The question was; do you have 12 Volt BETWEEN 1 and 2. NOT if you have 12 Volt between leg 1 and ground

 

[Placemotorsports]

Haven't checked across the two, I will do that tonight and update.

 

[Placemotorsports]

Yes, i have 12v across leg 1 and 2

 

[rmag757]

I think Ali FJ80 knows the deal, I had the same issue with water getting behind my windshield. My horn blew one day at work until it fried my horns. They would come on for 10 minutes then go off then on and off. Was not a very popular man at the school I teach at. My horns actually fried and had to be replaced. Had water dripping in at the bottom of my windshield on the driver side. Had the window replaced and now it leaks on the passenger.

 

[bjarnep]

After taking out the relay, measure if there is 12Volt between 1 and 2 (on the schematic) If you cannot measure 12 Volt, you have a problem with the relay, if you can measure 12 Volt - then the problem is between relay and horn contact.