Stock horn wiring and Stebel air horn

[Richouse]

My Stebel air horn is not working. I'm using a relay hook into the stock wiring and I'm pretty sure the relay is bad. My question is... BOTH wires that plug into the stock horn have power to them. Let me explain my install: I took off the right stock horn and replaced the horn with a relay. I plugged the 2 leads that WERE on the stock horn and plugged them into the posts on the relay. Another wire is going from the battery (fused) to the relay then from the relay to the Stebel horn. The Stebel is grounded to the frame. It worked great for a while but now its not working. (Yes I checked the fuse and it is good) The left stock horn is still installed on the bike and was never touched, this horn still works fine. I took my volt meter and touched the 4 posts on the relay. 3 of the 4 have power, the one going to the Stebel does not have power, and does not get power when the horn button is pushed. This seems odd to me because one of the stock wires should be a ground and the other supplies power to the stock horn when the button is pushed. Unless, there is ALWAYS power to the horn and the button grounds the circuit. Either way there shouldn't be power to BOTH wires??? I checked the wires to the left horn (stock horn left untouched) and both of those wires have power to them. It works as it should. This leads me to believe the relay is bad. But why do BOTH of the stock horn wires have power to them? and if thats the way its suppose to be how do I hook up the relay to make it work? Funny thing is, is it worked for a while then quit...

I hope this writeup is not to confusing.

Thanks,

Richard

 

[Queensland Ken]

Yep confusing.

But there IS power to the horns when the ignition is on.

They come on when the horn button is pushed and the switch sinks the current to a spider neutral connector (I think)

A mate had a short on the actual horn wiring that took out a fuse as the ignition was switched on.

 

[wfooshee]

The button connects ground, not power to the stock horn. On the stock horn, it's not grounded, with power supplied by the button, it's powered, with ground supplied by the button.

 

[ants_oz]

Its called "earth switching" or "ground switching". The system is quite common.

 

[Richouse]

Ok, now I understand the circuit. Now my question is do I hook the Stebel horn up the same way. I mean: run a (+) from the battery to the horn then run the ground to the relay and let the relay ground the horn? Right now I have it hook up the opposite: I have a (+) from the battery to the relay then the (+) to the horn and the horn is grounded to the frame. I don't think it would matter since the relay is just a switch. Would one way cause the relay to burn up?

 

[Queensland Ken]

Treat the relay as 2 separate circuits. Don't quote me

The 2 wires from the original horn circuit go across the relay, terminals 85 and 86, operates the coil of the relay. ( I have forgotten the designated relay numbers DOH )

The second circuit has a fused feed from the battery to one side of the relay contacts, terminal 30, the other side of the relay contacts, terminal 87, to the horn.

Then I would run a neutral from the horn straight back to the battery.

 

[wild1]

You said you hooked it up to the relay but we need to know exactly what pins on the relay you have going where.

 

[Geezer]

Is this the initial installation of the Stebel or did it work at one time and no longer works?

It is possible for the relay to be bad, or even for you to have the wrong type of relay for your application. Verify that the relay does in fact provide 12V to the Stebel when the horn button is pressed. I sounds like you already know how to do this, but just in case, Take your meter and put the plus lead on the wire to the Stebel where it plugs onto the horn, and the ground wire directly to the ground.

If you have power there, then the problem is either in the Stebel or, more likely, with your ground from the Stebel. As mentioned by Queensland Ken, it is better to run a ground wire directly from the Stebel to the battery.

If you don't have power to the Stebel when testing as descrbed above, then you'll have to verify the power is provided as expected at the output from the relay.

 

[Richouse]

It worked at one time and no longer works. So with that I'm assuming that I have the wires on the relay hooked up right. I have NO power coming out of the relay when the horn button is pushed. That leads me to believe the relay is bad. I went and picked up another relay this morning and will put it on here real soon.

 

[Richouse]

Well, It was a bad relay. Got the new on and it WORKS. Now I'm wondering why the relay went bad so quickly. It has not had a drop of water on it, I have not been in any rain at all lately. Not since I've put this horn on. It is by the radiator so it gets warm down there but these things are made to go under car hoods so I don't think it gets to hot. If the stock horn wires were put on backwards would it still work right but reduce the life of the relay? I really don't see how since it just looks for power flow to close the switch in it... The new one is a 12V 30A relay and I have a 20Amp fuse on it so it should be good to go. I'm just wondering what could have made it go bad (assuming it was not just a bad relay to begin with). I don't want to have to buy a relay every 2-3 months. I really don't use the horn very much at all but but when I want/NEED it I want it to work!!!

 

[Donal]

Well, It was a bad relay. Got the new on and it WORKS. Now I'm wondering why the relay went bad so quickly. It has not had a drop of water on it, I have not been in any rain at all lately. Not since I've put this horn on. It is by the radiator so it gets warm down there but these things are made to go under car hoods so I don't think it gets to hot. If the stock horn wires were put on backwards would it still work right but reduce the life of the relay? I really don't see how since it just looks for power flow to close the switch in it... The new one is a 12V 30A relay and I have a 20Amp fuse on it so it should be good to go. I'm just wondering what could have made it go bad (assuming it was not just a bad relay to begin with). I don't want to have to buy a relay every 2-3 months. I really don't use the horn very much at all but but when I want/NEED it I want it to work!!!

Your hook-up sounds fine, proved by the fact that it works! The problem (as you discovered) is in the relay where it sounds like the contacts have 'burnt out'. This could be due to the sort of load the Stebel is imposing. It is basically a motor (which drives an air compressor) so is an inductive load. The problem with this sort of load is that it can cause arcing when the contacts open, eventually leading to 'burnt-out' contacts.

Was the original relay which you fitted the one supplied by Stebel specifically for this purpose?

Just how often are you using this thing?????

 

[Richouse]

Well, It was a bad relay. Got the new on and it WORKS. Now I'm wondering why the relay went bad so quickly. It has not had a drop of water on it, I have not been in any rain at all lately. Not since I've put this horn on. It is by the radiator so it gets warm down there but these things are made to go under car hoods so I don't think it gets to hot. If the stock horn wires were put on backwards would it still work right but reduce the life of the relay? I really don't see how since it just looks for power flow to close the switch in it... The new one is a 12V 30A relay and I have a 20Amp fuse on it so it should be good to go. I'm just wondering what could have made it go bad (assuming it was not just a bad relay to begin with). I don't want to have to buy a relay every 2-3 months. I really don't use the horn very much at all but but when I want/NEED it I want it to work!!!

Your hook-up sounds fine, proved by the fact that it works! The problem (as you discovered) is in the relay where it sounds like the contacts have 'burnt out'. This could be due to the sort of load the Stebel is imposing. It is basically a motor (which drives an air compressor) so is an inductive load. The problem with this sort of load is that it can cause arcing when the contacts open, eventually leading to 'burnt-out' contacts.

Was the original relay which you fitted the one supplied by Stebel specifically for this purpose?

Just how often are you using this thing?????

Yes, the original relay came with the horn. I really don't use it much at all. I guess it was just a bad relay. If the new one goes out soon then I will look more into it. I'm just going to ride now...

 

[FJRandy]

• The Stebel horn NEEDS to be grounded DIRECTLY to the battery. You blew the relay (you didn't say which brand and it does matter) because most likely the current rose too high for the relay to handle. If your connections are solid, look for a TYCO relay. It's the only true waterproof relay out there. This is what I use on all my horn harnesses. TYCO is the same as the old Bosch relay. They bought Bosch's relay division. Also you might want to make sure the wires to pin 30, and the output to horn are 10 gauge with a 30 amp fuse. Donal above is correct. The current path is disturbed by not grounding directly to the battery. This increases current through the contacts and leads to burnout. Use 10 ga wire from horn to battery.

 

[HotRodZilla]

I wouldn't stress the relay going bad. They do it all the time. For instance: My wife's expedition is on its third blinker relay. My 13 year old F150 with 130k on it is still on the original blinker relay.

I have seen enough bad relays on enough different stuff that I think QC on most relays basically sucks. You get lucky or you don't.