# Horn and Horn2 fuses



## snowman9000 (Sep 16, 2006)

I have searched on this but haven't found the answer. What are the functions of the fuses called Horn and Horn2? Obviously one of them protects the horn circuit. But why are there two of them? I'm not talking about the relay, just the fuses by the battery.

Read on if you want to follow my horn troubleshooting so far.

I have an 01 Sentra SE and the horn does not work, not from the steering wheel or the panic button.

I tested the horn in place by jumping a wire from the positive terminal of the battery to the horn, and the horn works. So it's not a bad ground.

There are two horn fuses by the battery. Horn and Horn2. Both are good, and there are 12 volts present in the sockets for each of the fuses.

On the passenger side fenderwell there is a relay box with a horn relay. I removed the relay, applied 12V to the 1 & 2 contacts per the diagram on the relay, and it clicked, so it works. 

I tested the relay socket, and there is not any power across 1 & 2 when the horn button is pressed. So that's not good.

One of the other wires at that relay is the green with yellow stripe that apparently goes to the horn. I tested it for continuity from the socket to the horn connector, and there is continuity. That wire seems good.

So where I think I am is this:
Since the panic alarm also doesn't work, I'm assuming it's not the steering wheel horn button.
It sounds to me the problem is between the fuses by the battery, and the relay by the other fender. Like a bad wire. I'm going to open up the fuse box, and the relay box again, to see if I can find the same wire in each box, then I'll test it. But it would be interesting to know what the fuses Horn and Horn2 protect.

-Don M


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## NHxj4x4 (Aug 3, 2004)

I have the EXACT same problem in an 02 Spec V, and I cannot figure it out either. I'm almost ready to break down and wire a frikkin push button inside somewhere. If you figure this out PLEASE let me know!!

Thanks!


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## jcrow (Sep 27, 2005)

A couple of question for ya.

If you test relay socket terminal 2 to ground what do you get? You should get 12vdc. If not then it is the wire that goes to the fuse to the relay. Oh yes the fuse that feeds your horn is fuse #33. 

Now test relay socket # 1 to ground using the OHM setting on your meter while someone press down on the horn button. Knowing the ohm number is important because if the reading is too high the relay will not close. You should get less the 5ohms (not 5M or 5K ohms).

If you get a high number then the wire is bad, and if that is the case you need to run a new wire all the way back to where the wire is bad.

Note: touch your meter leads together in the ohm setting, you should also get a low number minus that number from the above ohm reading and that is your true resistance reading on the wire. 

Lets go from there and see what ya get.
Good Luck!


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## brollyson (Oct 25, 2006)

*2000 Nissan Horn Problems*

I have a 2000 Nissan Sentra and I have been having some horn issues - quite frankly its about to drive me nuts. I started by putting a new relay in and that did nothing apart from taking 15 bucks out of my pocket. Next I did some troubleshooting from the horn relay (right side of car) to the fuse panel (left side of car under hood). I determined that the wire fromt he fuse box to the horn relay connector was bad. I replaced the wire and boom the horn worked great. I tested it tested it tested it and it was all good.

Now I dropped it off one evening for an inspection and next morning they called me up and told me they had to reject it because the horn don't work. I was outraged. Anyway, tested it some again - the wire i replaced is still fine, the wire to the actual horn is fine, the horn itself is fine, the relay is fine. the only thing I haven't chased down is the 3rd wire from the relay - i assume it goes somewhere near the steering wheel horn button. I may have damaged it in the process of putting all the rest back in place. Anyway, any ideas or solutions from the nissan profesisonals. I called a nissan dealer and they more or less told me that if they give all the info out they would be out of a job. Like i'll buy another nissan.
thanks for any help folks.


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## snowman9000 (Sep 16, 2006)

I fixed my 2001. There are 4 wires in the relay socket. Two should be hot all the time. One is the ground wire coming from the horn button. The last one goes to the horn.

If you look at the socket as an upside down T shape, the wires are like this:
. .3
. .5
1 - 2

NOTE: My relay itself shows a diagram with 1 & 2 swapped. I looked at a service manual, which shows it how I typed it, and it corresponds to the mapping I'm giving next. Or go by the wire colors, but you have to get under the socket to see them.

3 (green/yellow) goes to the horn.
2 (white/green) comes from the horn button (a ground when the button is pressed).
5 & 1 (both are green/brown) are tied together somewhere in the harness and are hot. 5 provides power to the relay coil, just waiting for the ground to close on 2. 1 is on the switched side of the relay, sending the hot down to the horn on 3.

So the basic troubleshooting is:
1 & 5 should have 12v at all times. If they don't, pull underhood fuse 33 and check for 12v there. If it's there but not at 1 &5 in the relay, run a new wire from the fuse box to wires 1 & 5. I can provide the location of the fuse box wire. You can do continuity check with fuse 33 socket to verify this: It is in a 6 wire (3 across by 2 rows deep) white plug underneath the fuses. The wire is green/brown and is the middle wire in the row by the plug catch thingy. From what I've read on the net, this wire is a common failure. It failed on mine.

#2 should make a ground when the horn button is pressed. If not, good luck.

#3 should test for continuity to the horn terminal. If it's bad, that's an easy replacement.

Once I had power to my horn, it still did not work well. I had to remove it and clean the ground mounting.

This wiring running in front of the radiator must be crappy because the prior owner already hijacked a different power wire to replace a dead one for the windshield washer pump.

Good luck. Email me if I can help.

-Don M


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## OutdoorGuy (May 3, 2010)

I'm trying to fix the horn on my wife's 2002 Nissan Sentra. How do I get under the relay and fuse box to change the wires?

Rob


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## chimmike (Oct 17, 2002)

unscrew 'em.


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