Train Horn Relay Woes

Let me start by saying I'm no electrician - I think I understand just enough to be dangerous and accomplish a few things. I also don't know all the fancy names for things, so I'm sorry if I speak laymen here.

My relay for my train horn keeps dying and I don't know why, so I thought I'd ask the expertise here.
Here's how I understand a relay (and I know there are fancy numbers or whatever to call them, but I don't know those, so I'll just explain it as I know it). I have four posts:

1. Ground
2. Switching Current
3. Input Current
4. Output Current

I have my ground grounded. I have my output running to my train horn solenoid. I have my normal horn spliced into the switching current. I have Aux 3 switch running to the Input current.

The idea is if I have Aux 3 switched to ON, I have a train horn (and a normal horn, but you can't hear it). If it's off, I just have a normal horn - yeah, it throws the relay, but with no power from Aux 3, it does nothing. All make sense?

Here's the issue. The relay dies every so often. It just stops working. I've used a couple different flavors - ones from the parts store, a couple I've bought online, and all seem to die relatively soon (and for some reason ALWAYS at the sand dunes, though that might just be dumb luck).

What am I doing wrong here? It seems pretty simple. This last time I even put that battery terminal protector on my connections (which are all also protected by heat shrink. No dice. The only change I can think of making is reversing the horn/Aux3, but I don't know why that would change things. When it dies, I just bypass the relay by hooking Aux 3 straight up to the solenoid, then I can honk with the Aux 3 if I want, but that's not nearly as much fun.

You guys are smart, what's going on?

Give us the specific pin numbers you wire to on the relay and mainly, exactly where are you tapping into the OEM horn.

Ironhorse07 said:

Give us the specific pin numbers you wire to on the relay and mainly, exactly where are you tapping into the OEM horn.

Click to expand...

Well frack, I'll get the numbers tonight, but I'm tapping into the OEM horn power (not ground) just before the actual horn.

How SHOULD it be wired, number-wise? I'll be honest, I don't know what those numbers mean, but with a multi-meter and a 12v I can hook it up how I think it's right! And it DOES work for a while.

Edit*********************
Ok, looked it up, here's how I'm wired.
-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)

Sooooo,
30 = Aux 3
85 = Ground/Body
86 = Spliced from Horn
87 = Horn Solenoid

If it helps, I tend to usually have Aux 3 ON (Train horn active). Who wants a normal horn? But I'll flip it off if I'm getting it washed or worked on so that the guys don't do their little "I'm coming around the corner" honk and make their co-workers deaf.

Okay, then it should be:

pin 85 or 86 to ground
the other, 85 or 86 to the OEM horn
pin 30 to upfitter 3
pin 87 to horn solenoind

should be a drawing with pin numbers printed on the relay

Ironhorse07 said:

Okay, then it should be:

pin 85 or 86 to ground
the other, 85 or 86 to the OEM horn
pin 30 to upfitter 3
pin 87 to horn solenoind

should be a drawing with pin numbers printed on the relay

Click to expand...

Well crap, looks like I got it right - though I don't think I could have it wrong and still have it work. So why do my relays keep dying? I've used different kinds. It looks like I'm wired up right. The only thing I can think of is that they aren't protected enough and are getting corroded or something.

your wired right. where is the relay mounted?

TO OP, just curious - what kind of train horn system do you have and how long does it work before it craps out? I had the same thing happen to me with my Kleinn horns but Kleinn sent me a new relay harness and it's worked fine for the past few weeks.

Ironhorse07 said:

your wired right. where is the relay mounted?

Click to expand...

It's basically in front of the radiator, passenger side, zip-tied to some other wires. It's just inbetween the real horn and the train horn, which is hiding in the passenger side of my stock bumper.

---------- Post added at 10:26 AM ---------- Previous post was at 10:21 AM ----------

goinsvt said:

TO OP, just curious - what kind of train horn system do you have and how long does it work before it craps out? I had the same thing happen to me with my Kleinn horns but Kleinn sent me a new relay harness and it's worked fine for the past few weeks.

Click to expand...

Well, no simple answer here since it's pieced together. The train horn was just a bonus to my onboard air system - but not the intent.

I have two 480c compressors from Airbagit.com
I have some random 5 gallon semi air tank
My actual train horn is some random train horn I bought from some dude on Craigslist, except I've replaced the solenoid with a solenoid from some truck stop in commerce city (because the solenoid died).

How long it works is pretty random. The previous relay lasted months. The most recent relay only a couple weeks - and was probably used maybe a dozen times? The current relays were an eBay purchase.

So, pretty pieced together.

That does not sound like the ideal mounting location. I have a Kleinn and the relay is mounted by the compressor but it is sealed pretty good with heat shrink and pointed to run water off not in. I don't think the majority of the Bosc style relays are considered weather resistant much less weather proof.

Ironhorse07 said:

That does not sound like the ideal mounting location. I have a Kleinn and the relay is mounted by the compressor but it is sealed pretty good with heat shrink and pointed to run water off not in. I don't think the majority of the Bosc style relays are considered weather resistant much less weather proof.

Click to expand...

Yup, I'm thinking I need to tuck it away somewhere safer. That's really the only thing I can think of. I'll add that to my to-do list and see how it goes.