Where is ignition and horn wire?

Installation Help & Advice Horn Kits
1

I am installing the k5 into a 2009 GMC duramax. How am I suppose to know where the ignition wire is or the load wire for horn???

Anyone know how to find them or their color or anything. Seems like this kind of referenced info should have been included or supplied per customer.

2

I drive a different car but I found mine along with the other bunch of wires in the fuse box. you just need a little patience probing each one with a needle and a test light until you find it.

3

If all else fails - the horn wire is at the horn…lol
I have an 09 GMC and will have to do the same thing. Get in the fusebox with a test light or DVM like djQUAN said.

4

Just find the horn and take it from there.