Tried to fix someones hack job now my horn doesn’t work

[Blackdrag450r]

so I purchased a 2012 ppv with low miles but I found it has some quirks. Going over every single hole on the vehicle I noticed there was a small hole drilled into the firewall and a small wire going into the cab. I work on all my own vehicles but electrical is not my strong suit. I got rid of the wire and now my horn doesnt work. The wire was tapped into the terminal block underneath fuse #37 which is SEO B2. The wire was for some reason wrapped and soldered around 2 tan wires on this plug underneath the steering column which I am assuming is the plug for the whole steering column. The wires are soldered together in a big blob under the electrical tape. What a hack! Also I do not have the option code for the horn running the sirens.

 

[Blackdrag450r]

Does anyone think I should start with separating the tan wires under the dash? They are a mess under the tape and I don’t know which one goes to which as they are the same color.
Upon some further investigation it turns out I do have option 6j4 even though its not on my rpo sticker. I tried connecting the tan wires under the dash together and still no dice.

 

[techbiker]

Does anyone think I should start with separating the tan wires under the dash? They are a mess under the tape and I don’t know which one goes to which as they are the same color.
Upon some further investigation it turns out I do have option 6j4 even though its not on my rpo sticker. I tried connecting the tan wires under the dash together and still no dice. View attachment 188200

-Do you have the PPV owner's supplemental manual? If not, I will scan mine in if I get some time.
-Do you have a factory service manual?

I would be careful before removing too many wires unless you have the FSM. The electrical systems on these Tahoes are complex. What you really need to do is buy a FSM, open up the wiring diagrams, and trace the horn wire. You might be able to reconnect the factory horn wire. Sorry I cannot help more!

 

[Blackdrag450r]

The bad part is that this thing didn’t come with any manuals whatsoever. Thanks for the help.

 

[2011SSVHOE]

The bad part is that this thing didn’t come with any manuals whatsoever. Thanks for the help.

this should help you Chad,

 

[MidwestMike]

Does anyone think I should start with separating the tan wires under the dash? They are a mess under the tape and I don’t know which one goes to which as they are the same color.

I'm going the other way, or looking at the picture wrong. I'm seeing two tan/brown wires, and think they need to be connected for the horn to work.

This option let you use the horn switch to hit the siren. When connected together the horn worked, but it gave the fitter the option to connect the brown from the horn button to the siren.

Can start testing easily. Stick a meter on there and hit the horn, does one of the wires end up getting 12 volts?
(The gutsier move is to put 12 volts in and see if the horn goes off, but I'm not a fan of sending 12 volts somewhere when I don't know where it is going.

As for the wiring diagram, you can find nice big, easy to read ones anywhere. Get the manual for all the police-type options real easy.

https://www.google.com/search?q=wiring+diagram+for+option+6j4+&ie=utf-8&oe=utf-8&client=firefox-b-1