Horn problem...Is my Matrix possessed?

[fr0zen]

I'm having horn problems that scare me so much that I feel like crying!

I got my cute yellow 2004 Matrix XR back in 2003 and have had no problems at all with it until now...

The horn randomly goes off like it's possessed. At very inoportune moments - like when someone is crossing the road or I'm driving down the highway. It's even gone off when it had been parked for hours in the snow behind my house.

The first time it happened I'd been driving the car for 3 hours or so. My boyfriend was in the passenger seat and thought I was screwing around, but I even turned the car off and the horn kept going. I've discovered that if I hit it, it will turn off. It seems completely random, though acutually using the horn increases the chance. It's a steady honk until I start panicing and punching the horn. Most of the time it will stop for at least a few seconds. It will go for days without going off by itself. There doesn't seem to be any other symptoms though in my panic sometimes it feels like the steering is weird, but I think that's only my startlement.

What oh what could it be? I really don't want so many people angry with me for irrational honking (and me punching it to get it to stop just makes it look that much worse). Plus I just moved to VT from CT and apparently CT people are well hated here. I'm thinking of just disabling it - I could probably figure out how, but having a horn is kinda useful...

Any ideas?

[spin156]

I had a problem with my old '90 Toyota pickup that was just like you describe. And, it happenned in similar weather conditions to what we are having in N.E. right now - very cold, freezing rain, cycling back and forth through freezing. I suspect that water got into the horn and intermittently shorted it causing it to go off.

Ok, that's only speculation. It only happenned for a few days and never happenned again.
Go figure.

At worst, you should be able to get a boneyard horn for just a few bucks.

Good luck with the exorcism ;-)

[XR2003]

Possibly horn relay fuse is bad - or the weather somehow got your horn sensor in the steering wheel stuck where it touches the sensor.
Try searching for the fuse that the horn is connected with to disable the horn as a short term solution.
By the way - fuses are found under the steering wheel to the left and also under the hood near the battery.

Good luck!

[spin156]

Both the horn fuse (10A) and horn relay are in the engine compartment fuse box (aft of the battery).

There are four, or five (if you have VIP security system) components involved in actuating the horn:

1. Horn
2. Horn fuse
3. Horn relay
4. Combination switch (i.e. horn button on your steering wheel)
5. TVIP ECU (security system computer).

I would be most suspicious of the horn relay or the horn itself. As I said earlier, you may have a condensation/icing problem. I believe the horn relay is the same as at least two other relays in the fuse box, so you could try swapping with a like relay. The chance that a fuse is intermittent is so rare that it's almost not worth consideration. However, you could just pull the fuse, inspect it (i.e. look at it and see if it's blown), and then re-install in the fuse box. There is that very tiny chance that it was not seated properly, or one of the fuse box contacts is not making good contact. Take a good look at those contacts and see that they are clean and squeezing properly. While you are in the fuse box, take a good look and make sure everything is clean and dry. See if the cover to the fuse box was on securely when you take it off. Look at the horn and see if it's iced up.

I think the components in the engine compartment (1,2, & 3) have got to be your most likely candidates. The TVIP ECU module sits behind the glove box and hopefully is not your problem. It would probably take a trip to the dealer to suss out that one. As far as the horn button itself, you should see how hard it is to blow the horn. It should take a good push on the switch. Try touching it lightly and tapping it with your finger. That may tell you something.

OK, that would be my approach to the sleuthing and/or exorcism. Enjoy ;-)

[fr0zen]

Yay! Thank you!

I have at least a temporary solution now. I'll pull the fuse this weekend, until it gets warmer out. Then when it gets above freezing I'll put it back and check the relay and the rest, just as you all suggest. Thank you! No more embarassing honks at inoportune moments