So the original horn had two wires going to the switch in the steering wheel. Why two? I have a ron francis wiring harness and it only has one horn wire which gets sent to the horn relay. But I was drunk when I was wiring up the column harness and dont exactly remember why I sent the yellow/blue wire to the relay and left the solid yellow wire open and on the dash, as if it were to be plugged into the dash or grounded. My haynes manual says nothing about the yellow wire..

Any hints? Besides the fact that I should'nt be drinking and doing wiring? (i burnt myself like 7 times with the soldering iron, but its ok I didnt feel it.. Lol)

 

And if it is just power to the switch in the wheel then out to the horn, what is the purpose of the horn relay?

 

for some weird reason I cannot find the horn switch in the 69 wiring diagram, so I'd knew what kinda colours you're talking about.

When a horn assembly has two cables that both connect to the horn button then it works as simple as the button connecting those two cables causing electricity to flow and eventually beep ...

When you only have a single wire then it usually works in conjunction with a horn relay. Basically the circuit is switched when you connect the single cable to ground.
in other words when the horn button is clamped into the steering wheel, a part of the ring is constantly connected to the ground. and when you press the button it connects the cable to this ground. This will allow electricity to flow through the relay which again results in a beep ;-)

i hope that kinda makes sense to you what the difference is between one cable and two cables setups

you could even work one cable switch without a relay as in the followiung schematic


battery+ ---- horn ----- switch --- ground

this is what is called a negative triggered switch (at least myt translation).

the horn _ALWAYS_ is connected to battery+ so for electricity to flow through the horn it needs ground on the other side of the cable. so thgis cable goes to your horn switch and there you just put it to ground when pressing. BUT for this to work you need two cables on the horn itself. the + cable that is always connected to battery+ (or ignition. doesn't matter just for this thought). If we would take ground from the chassis the horn is bolted to, then it would constantly beep. so we need this second connector to lead to the horn switch.
In my setup (1964 and I believe no other 60s mustang has that) it works with a relay. the horn is connected to ground. and the + cable to horn is switched over this relay.

hope thats any help and not just confusing ....

 

sadly i was drinking and wiring my self and have a nice scar on my shoulder from my dam horn wires. Sober up before this one and un hook the battery. The horn relay works when it gets grounded, hence when the wires touched my shoulder the horn worked!

 

Thanks guys!

Kalli,
Thats what I figured, I just was too lazy to look at the relay before posting.. and Im at work. So I guess what Ill do is ground the second wire coming from the horn switch since I already sent the other one to the relay/flasher assembly.

 

meant to start new thread not reply

 

I was wondering why i had wiring for two horns under the hood, I'm half tempted to get another one with a different tone and let them fight it out.

 

When you have the high and low pitch horn it sounds great.

When I first bought my car I had one cheap horn on there that you can buy at Autozone for like $10 that didn't work at all.

To get the horns to work I ended up buying a new repop hi and low pitch horn, replacing the head light harness and replacing the turn signal harness in my steering column. Actually, I didn't do all that just to get the horns working but they do work now, LOL!