Horn not working

[BrooklynBay]

That sign language only works for people which are able to see while they drive! Some people don't hear horns since the new cars are very sound insulated. They won't hear the horn if they have their stereo cranked up. Some people flash their brights.

 

[blak_betty]

Quick question for you guys.... which pin is pin 1 and which one is pin 3 as they both have the same orientation. I would suspect that pin 1 is the top one and pin 3 is the one below it on the relay. Also when I went out to check the voltage last night my pin 5 was pushed into the distribution box so that I could not access it. Might be a good reason for the horn not to work since I believethat is the power wire to the horn itself, either way it is not in the circuit if it is not being contacted... correct?

 

[budwich]

As I indicated, pin 5 brings IN the voltage... so if it ain't getting contact, you ain't getting voltage IN and you won't get voltage OUT. I think you now know "the rest of the story". As far as pin numbering, I do believe they are "etched" on the bottom or top of the relay. Outside of that, measuring resistance across a winding will give "some resistance", across closed contacts -> none, across disassociated pins will be infinity.

 

[blak_betty]

When you talk about resistance, should I be measuring that or the voltage?

 

[BrooklynBay]

Resistance is measured across the coil. The contacts are open until the coil energizes. Then the contacts should have continuity. In this case the contacts would provide a 12 volt circuit to the horn.

 

[blak_betty]

Okay, here we go again, I have no connection in the position where 4 is supposed to be

___ 3

___ 5

l l l
l l l
2 4 1


I think that is how it is and there is no wire leading to the middle on the bottom row. I hooked up the relay and tried to sound the horn and I blew a fuse. 3 is the blue wire that goes to the horns so it makes sense that they work when the horn is depressed, but I think I had voltage between 3 and 5 when the horn was not engaged. Thanks for all your troubleshooting.

 

[BrooklynBay]

This link might help you out: http://www.railway-technical.com/muops.shtml

 

[blak_betty]

Sorry Brooklyn, not too much help to me as I am science minded but physics isn't one of my strong points. What would cause me to blow a fuse, and should there be something in the middle position on the bottom row?

 

[BrooklynBay]

A short circuit (positive and negative meeting each other) would blow a fuse. Which arrow are you referring to? Is it the ground symbol called Earth?

 

[blak_betty]

In my post where I show what the relay looks like, it is the middle connection on the bottom row.

 

[budwich]

OK... there is no connection to 4... that is the "voltage OUT" contact when the horn is not depress... the voltage goes nowhere. All voltages are measured to a ground (negative on your battery terminal).... not between pins ....5 and 3 or otherwise. As I indicated, there should be voltage on 5,4 and 2 when the horn is not depressed and 5,3, and 2 when it is depressed. I am not sure when you said "I hooked up the relay and blew a fuse when I depressed the horn"..... please explain.

 

[blak_betty]

Okay, I am not quite sure what you are saying budwich, but you have been a great help here. I put my relay back in and when I pressed the horn the fuse blew. I have votage on 2 and 5 when the horn is not depressed as there is no wire for number 4. Number 3 does not have voltage with the horn is pressed, but there is still voltage on 2 and 5. Could there be a bad ground somewhere not allowing a complete circuit, there was not a ground wire from the horn so I connected a wire from the second horn to between the mounting hardware and the frame?

 

[budwich]

OK... now we are almost on the same page..... great with the 2 and 5. 4 doesn't matter but it should have voltage on it if you put a wire tab in holder as the relay isn't operating and it "sends" voltage from 5 to 4 in the non-operated "position". Anyways, something is obviously different from your "original posts" where you said you depressed your horn and heard a click.... you said nothing about blowing a fuse. Was it always blowing (and already blown when you originally detected you had no horn)? I suspect not but your "modification" is wrong and the likely source of your "new found" observation (fuse blowing). I don't believe there is meant to be a ground wire.... the horns get their ground from the mount hardware (ie. "self-ground"). Your problem still appears to be, as you observe, no voltage on 3 when the horn is depressed. This is no good. However, I am not sure that I understand this because if you are blowing the fuse when you depress the horn, you will never see that voltage as the fuse will go before your meter will respond. Best way is to isolate the relay from the horn and measure 3. By that, I mean disconnect the cable at the horn, measure voltage at your pins before you depress and again after. You should not blow any fuses. If you do, we have to investigate this a bit different looking for shorts and not voltages. Report back with your findings and we can go from there.

 

[CDW6212R]

Without reading every word thoroughly, I'll wonder this; Is the horn circuit a ground triggered system, by the two constant power wires that should be the case.

The bottom two terminals are the trigger wires. From post #26, the 1 & 2 terminals trigger the relay. The 3 & 5 terminals are the controlled circuit. If the relay has five terminals, then the 4 & 3 should test as no resistance by a meter. The #4 is for turning off a circuit with the relay, or switching a circuit.

I had my 99 horn to quit, and the connections seemed poor, so I bought a newest at junk yard horn set. What I got was a 2003 Sport set, they have two wires, they actually ground the horns separate from the cases.

Test that relay well, pull the horn wire first, confirm that the relay is sending power to the horns first.

 

[blak_betty]

It wasn't always blowing a fuse and when I originally looked the fuse was still intact. So by checking from the horn wire and the battery -ve terminal i can check the voltage to 3 when the horn is pressed, correct?

 

[budwich]

yep, you will basically be reading the voltage at 3 IF the relay operates upon depressing the horn (assuming the wire is detached from the horn) AND the fuse doesn't blow.

 

[blak_betty]

Will do that after supper and post back later. Thanks again.

 

[blak_betty]

So the saga ends... a happily ever after ending. Removed the wire to the horn and tested and this time I had power to it, no idea how or why, but I am not complaining. So I went and took the horns out again, took some sand paper to the frame where it contacts the hardware and put them back in, hooked them up and abracadabra, loud as hell horn now. Thanks for all your help with this one, even though I still have no idea what the problem was to begin with and where the fix is. Anyhow, now there is a good logarithmic work-through for others to use thanks to all the posts here. Moral of my story..... I think..... make sure all the contact points are meticulously clean to bare metal and no mods while working through the problem, like trying to add a ground when it obviously was not needed. Thanks again.

 

[CDW6212R]

Well done. That was my issue as well, I saw the corrosion of the mounting bolt, and decided that the later two wire horns would be better. My truck was a rollover, the battery had leaked, thus my corrosion was greater than a normal truck. Regards,

 

[budwich]

great.... your actual problem wasn't "no voltage" but no ground... which the horns were missing. It took a while for us to "talk the same language" and convey the appropriate observations, but we / you made. I hope you didn't permanent lose any "hearing" during the "inadvertant" horn test, they are loud, probably the loudest I have hear cause of the duals....