1999 Nissan Frontier 3.3 horn issue

All, I need some assistance with electrical troubleshooting ad I’m not that great, trying to learn. I want to do this the right way.
My issue is, horn doesn’t operate unless I powered it up directly at horn. It has a 3 pin relay, one has power and nothing on the other two pins. I took the clock spring out and checked resistance or ohm it out from one point to the other and nothing. I’m thinking that is the problem. On the electrical diagram, it shows a horn switch with a red wire, but not sure where it is. There are two sets of contacts behind the airbag in the steering wheel with a single white/brown wire going to one these contacts and the other one is bare without any connection to it. Not sure if these two contacts are the horn switch and how it operates as only one has a wire a wire to either of the two contacts. This is also where I’m lost.
The way I tried troubleshooting this was,
I placed a test light to ground and touched the light green/red on the spiral cable and nothing happened, was hoping to hear the horn if this is correct but did not. Also did the same with the brown cable, I tried doing the same at the yellow split clock spring connector and at the black connector on the steering wheel but nothing happened. This is where I am also confused to how it operates or troubleshoot it.
Any ideas will be greatly welcome, appreciated, specially if you are trying to teach me something. I want to learn. See pictures attached. If someone is able to guide me over the phone at your convince, would be great as well.

First of never use a testlight on any yellow connector that can set off airbags If testlight is hooked up incorrectly. Secondly get wiring diagrams and follow them. From what I see with what you provided. do you have power at the horn fuse and one pin of the relay? This is probably/ most likely a bad relay those cost about 5-8 bucks.

Thank you for including the diagram and photos. Here's how I'd do it in a flat rate environment. Find pin 1 (light green/red) at the relay socket, connect your test light to B+ and gently probe pin 1. Hit the horn. Does the light shine brighty?

Find pin 2 and 3, relay socket. Short across them with a jumper/paper clip/whatever. Does the horn sound?

If yes to both, the relay sucks. :lol: Time for a new one, like Hardtopdr2 suggested. If you want to flat rate it even more, see if there's another three-pin relay in the same box. Swap it and try the horn again.

From an educational standpoint, the first test proves the clockspring, the horn contacts, and all the wiring/connections in between are capable of carrying enough current to activate the control side of a relay. If your test light didn't light, you'd move closer to the horn contact and recheck. Connector Z5, for example. If it now lights, you went past the problem. If it still doesn't light, try on the other side of the clockspring.

The second test proves the fuse, the relay socket contacts, the horn wiring and the horn itself. So, if the rest of the circuit works, then you've eliminated everything but the relay.

Yes there was power at the fuse on pin 2, pin 1 and 3 side of relay, there was nothing. As far as the yellow connector I mentioned, the air bag connector which has wires yellow and white gray was disconnected from steering wheel after disconnecting the battery ground cable. After re attaching the ground cable to the battery is when I checked at yellow connector.
Now my other concern is, if there was no continuity at either side of the clock spring, does that means its bad? There is an incoming yellow connector to the clock spring with a 3 pin black connector at the other end (steering wheel side) and no continuity present. Would that mean is open inside?

Thanks

Tyler, Once I get back to the vehicle, will check on your suggestions and will let you know what I find. Thanks for the explanation. Also, my other concern would be, why does the horn contact has only a wire to one side and the other side no wire at all? How does this works like this? Lastly, is the two metal contacts the horn switch?

Thanks
Josh

joshuamal wrote: Also, my other concern would be, why does the horn contact has only a wire to one side and the other side no wire at all? How does this works like this?

Because the other side of the contact is permanently connected to ground, through the steering column itself. Because the switch closes when you hit the horn, the horn relay (and your test light) will find a path to ground through the horn switch.

Lastly, is the two metal contacts the horn switch?

Probably? I don't have the steering in front of me. :silly: