Installing Motohorns - Can't seem to pull signal from OEM horn?

Anyone install aftermarket horns, like the Motohorn? I am installing two.. I tried to do T-Tap's off of the purple wires coming from the passenger side OEM horn to a relay. Two wires, from what i've read polarity doesn't matter. Unfortunately, doesn't work. I can run the horns if i run signal from my Auxbeam switch panel to the relay, but not if i try to t-tap from the OEM. My version of the auxbeam doesn't have a momentary feature (BA80), so it's less than ideal.

Not sure what i'm missing - but looking for ideas. I'd prefer to run these with the OEM horn if at all possible.

 

Interesting discovery. I had horns on my 2006 Tundra wired like you described and was planning on transplanting them into my 2023.

 

CANBUS might be your issue. Same issue trying to tap high beams for offroad light trigger.

 

Damn CANBUS...

 

If that is the problem and this reader works for you DM me. I went a different way with my high beam trigger issue.

https://www.tundras.com/threads/can-m8-canbus-reader.160659/

 

I installed aftermarket horns, CANBUS is NOT AN ISSUE AT ALL. The horn uses standard 12V.

You can use

NEOGET Car Horn Connector Adapter Wiring Harness, Compatible with Toyota Lexus, 2 Pack Pigtail Converter for Universal to OEM Horn Replacement (Toyota)

THIS ADAPTER so you don't have to cut the factory wiring and use the original horn wiring for you +12V signal. I used this to my relay for my dual air horns so I can just press the center of steering wheel to blow the horn just like OEM.

 

What year is your Tundra? Is this just a wire and a plug that mates to the OEM harness?

I poked around and discovered that the CANBUS is very sensitive about electrical resistance values. Which is why the OP couldn't get his aftermarket horn to work when tapping the stock harness for a relay trigger, since it changes the resistance in the circuit.

Apparently this issue can be remedied with a resistor of the proper value installed in the circuit.

 

This is the 3rd Gen forum, I have a 3rd Gen tundra. All the 3rd Gen have the same horn wiring.

The stock horn harness is not CANBUS. It is simple 12v

 

Thank you! So the connector goes from relay in to the factory horn harness, and the other lead goes from relay to ground? Seems simple enough, i'll give it a go.

 

That's correct.

 

IF that were only true

 

From what I did the factory horn is being used as a 12 volt horn with the OEM wire being the trigger off the relay. This is how I e is working

 

I'm pretty sure @GREENPUS 's response was sarcastic as we get 2.5 guys jumping in all the time. Lol