Help Kill Gremlin!

I swapped out the horns on my 2017 Tacoma TRD Sport. For 20 minutes they worked from the steering column button, until they didn't. Every other switch in the steering column (i.e. clock spring) works fine! They work fine with the panic switch on the key fob, so the fuses and relays must be intact...So where is the problem?

 

Try holding down the horn button while turning the steering wheel and see if they work intermittently, if they do then it's a failing clockspring.

 

Thank you for writing!
I tried that, and I also checked the other switches that go through the clock spring: they all work.
It's so weird!

 

Don't expose them to bright light, don't let them get wet, and never feed them after midnight.

 

If you have two identical relays in the box you could swap them to further rule that out.

Could swap horns back to see if the behavior changes.

Does sound clock springy, though, just looking at the symptoms and not the timing

 

yes, thank you Greg, I can't see any way around pulling the steering wheel and getting a multimeter to the clock spring. Argh. Even though I suspect the problem's in the connecting between the push-pad over the airbag, and the contacts in the column.

 

I think several of your assumptions are incorrect.
1) The noise maker in Panic Mode from the FOB is a different noise maker - think you will find that noise maker on the right fender near the fire wall. I don't remember exactly where it is as I have moved mine.
2) Check the 10 AMP HORN fuse.
3) Swap in another relay as already suggested.
4) If you were my neighbor and you used the horn for 20 minutes, I would find a way to silence them too. Ask your neighbor what they did.

See schematic below:

 

It seems odd to me that changing the horns would make the horn button not work/cause clockspring failure, but everything I find points to that.

Out of curiosity, are you sure the horn button worked before you started?

 

Thank you for posting, and I hasten to assure you that I tested the horn on the road, not right next to my neighbors. I will look for the panic button noisemaker that you mentioned, having already swapped relays and replaced fuses.

 

Just ribbing you on the neighbors.

Next round:
1) Put back the original horns and see if they work.
2) Remove the new horns and bench test with a 12VDC supply to see if they still work.
3) Remove relay and short pins 3 & 5 together with a heavy gauge wire - this will provide power directly to the horns without the use of the relay, spiral cable or horn button. The fuse will still be in the circuit protecting any overload.

All this assumes you do not have a multimeter to do a proper diagnosis. Which is still hard with access to test points limited.

 

The KEY was being told that the panic alarm is NOT the horn.. Who knew? There is a separate noise maker for the panic switch? duh!
... As soon as I learned that, I realized there must be a bad fuse or short to my fancy new horn. I found it, fixed it, and now I am horny again! Thank you, anonymous web friends, for all your attention, help, and, ultimately, solution to my problem! Maybe this internet thing has some potential after all...

 

Would you be so kind as to tell us specifically what fixed it?

I’ve counted at least 6 different noise makers on my truck.

 

It's embarassing to answer that, but I have to admit that it was the 10amp horn fuse..
I never knew there was a separate "horn" (noise maker) for the key fob panic button.
When I pressed that button and heard a horn toot, I assumed the fuse and relay were ok.
The relay was, the fuse wasn't. (Which makes sense: the new horn pulls more power.)