my 1984 EVTM does not agree to the wiring colors as compared to my 1985 cab, where in the horn diagram, 1984 shows a Dark blue and 2 Black wires coming in and out of the horn/cruise pad, but my 85 really has a yellow wire, dark blue wire, and a black wire.
Also the pin location does not agree with the true location of the wires in the connector...

 

Not 1985, but here's 1986: Horn & Cigar Lighter - ???Gary's Garagemahal. And here's 1981, which shows a blue/black hash: Horn, Speed Control, & Cigar Lighter: - ???Gary's Garagemahal. But neither have what you describe. Interesting.

 

Here's two Cruise horn pads showing the Yellow wire, Blue wire, and black "ground" yet it is not a ground?"


It appears the Blue wire has nothing to do with the Horn... if the yellow (power) wire is "grounded" the horn blows.....interesting.....

 

Confusing. Here are two shots of the 1986 EVTM. The first is from the Horn page and shows DB, which is Dark Blue, and BK wires coming from the pad, but doesn't ID the color of the 3rd wire. But in the 2nd pic, from the Speed Control page, we see the 3rd wire is Light Blue with a Black stripe.

But, your pads have the Dark Blue power wire as Yellow!? (The third pad is non-cruise, right?) Are both of those 1985 pads?

 

Whats more confusing is there are 2 brushes on the column, that contact the steering wheel. the "outer ring" on the wheel mates to the "outer brush" which connects to the Yellow wire on the pad.

The inner brush, which mates to the inner circle has nothing to do with the Horn.

But, with a cruise wheel, you "plug" in the black wire into either threaded hole that is used to pull the wheel, But my horn only works sporadically. I found the center of the column is not making a real good ground, because if I jump the ground wire while plugged into the wheel hole and the horn does not work, connect the jumper to any known good ground and the horn is reliable.

Question is....is there a "third brush" somewhere in the column itself that completes a ground circuit to the rest of the chassis? I ask this because where you are "Grounding" the wheel at the pad is a rotating shaft, there needs to be some type of positive contact to the rotating shaft to complete the ground to the system....

 

Eagle Eye - Go back and look at the two drawings I included. The second one shows three brushes. Want me to circle them so's you can find them?

 

You mean I need to put on my glasses??

 

Well, lookey there, a third brush, Now where might that be on the column........

 

Yes, but not your SUN glasses! Cheaters. Bifocals, preferably.

 

I highlighted things so's you can find them:

 

Found it! Me thinks the column either does not have the brush, or there is no spring tension on it. I checked the other two columns I have, the they both have them but one is recessed (no spring tension) the other is fine, Now to dig into the one on the truck to see if it has one.......

 

So, you are wearing the cheaters I take it. Everything is becoming clear?

 

Naw, had my daughter (the 10 year old Welder, Painter) point it out.. easier that way

 

Either way, you were using a "cheater".

 

Once again Gary, We make a great team!
I'm the idiot, and you bale me out!
The column I'm using is for the standard tranny cab that did not have cruise.

The "new" rust free cab I'm using was an auto with Cruise.

The standard column did not have the "third" column ground brush. That's why the horn would only work when the truck was off, (was grounding through the wheel lock-pin?)
Installed the ground pin from the automatic column and horn works like it's supposed to!
Now maybe, just maybe the cruise will work too????? Na, can't be that easy.....