Multiple issues with horn wiring

Hey all, having some issues with the horn on my 2011 DCLB 6cyl. Recently, the horn stopped working, so came over to TW to see who else had had the issue and found a fix. Found a lot of info on spiral cables, but figured I'd start simple and replace the fuse.

Replacing the 10A fuse under the hood fixed it, awesome. Horn worked when truck was off. A few hours later, I started it to drive to the store, no horn. I checked the fuse and it wasn't blown. Replaced it anyways, still no horn and new fuse didn't blow.

At this point it would seem like either the spiral cable or the relay, but I'm confused since the fuse fixed it the first time around. What are the chances both issues would happen at the same time, or am I missing something? Radio buttons on wheel still work.

 

Had an issue with my 2007 that one of the horns had failed but it was intermittent. Finally, it failed for good and then neither of the 2 horns worked.

 

There are multiple ways to check it.

1. Unplug the horn and check for power when the horn is pressed.
2. Test the relay.

If you are careful, and have access to a wiring diagram

3. Test the ground side of the relay terminal for continuity when the horn is pressed.

When you press the horn it grounds the relay.
Remove the relay.
Probe the ground terminal of the relay (not the relay, the spot where it plugs in)
Press the horn and see if you have continuity.



@Jimmyh

The above method should work, right?

 

Yes.

I would start at the horn power wire(s) first.

Unplug the horn(s). Connect meter to one of the wires and ground with the other lead. When you mash the horn button you should get 12 VDC if you don't then have someone move the steering wheel and mashing the horn as you are reading voltage if it comes and goes it is the spiral cable.

------------->Horn Wire-----> Meter Red Lead----->Volt Meter set to VDC----------->Meter Black Lead------> Chassis Ground or Battery Neg Terminal

 

Awesome, thanks for your help! I'll start here today and see what I can find.

So to confirm, unplug both horns, but test with the meter one at a time?

 

So, before I started taking stuff apart I tried cranking the wheel all the way to both sides and pressing the horn, and it worked. Pretty sure I can safely assume it's the spiral cable at this point. Any expert consensus on $26 Amazon replacement vs. $200+ OEM?

 

I’d feel safe with doing the spiral cable at this point.
As for OEM or Amazon, I can’t help.
I went OEM, only because Toyota sent me a recall on it.

Maybe others will jump in an give some feedback.

 

Yes.

And it looks like you have it isolated already.

Good job