Does anyone know where the actual contact to ground is made in the horn button? Horns work fine on separate switch to ground,but do not function with button. I have it apart and cant tell if the contact is made in the button itself or some how through the brass rod.It seems to me that the brass rod and spring and bushing serve to hold the button out and contact is made inside when depressed. Is this correct?
Thanks DJ
DJ,
The horn push button presses down on the rod which is in contact with Purple/black wire via the brass contact ring in the steering column. The overall column is grounded.
On my 65, if I remove the steering wheel (I have a quick disconnect) and push down all the way on the horn rod, it does nothing. The steering wheel has to be on the car. So part of the circuit goes through the horn button, which is metal under the emblem.
The rod simply accommodates the telescoping feature of the column while providing a ground path when the button is depressed. Inward movement of the brass rod does not close the circuit by itself…it’s just a “slider” that (electrically) interconnects the fixed inner, and telescoping outer column sections. As Phil explained, only when the metal ring on the back of the button touches the wheel hub is the ground side of the circuit closed (via the brass rod, the sliding contactor on the shaft, and the wiring that John described).
If the button isn’t working, there’s something going on with the wiring, or perhaps the “brush” that rides on the shaft.
Appreciate the comebacks.The wiring is all new and everything is operational on the car except the horn.When the wire that is connected to the top of column via unprotected female receptacle is grounded the horn beeps. I will take a hard look at the button mechanism in the AM.
Again thanks for all replies. Have a much better insight now. DJ
I believe that whatever is inside the inner shaft to ground the brass rod is missing or just not making contact.Looking at my parts catalog I can see a lower bushing and a sleeve that goes inside the inner shaft. The rod must make contact to one of those when button is depressed.
Can you just slide out the innershaft to check? Thanks DJ
Yup, it slips right out and back in. Testing my memory I seem to recall two copper contacts in there, one a ring around the inner column and the second a flat bent brush thing. I can’t recall the orientation of them though or how they make contact.
It’s been a while since I had that mess apart, so I’m going from memory…
I’m looking at Plate 31 in the steering column section of the Parts manual (same as figure 6 in the steering section of the 3.8 shop manual). There could be a problem with Item #17 “contact nipple”, which keeps the brass rod in contact with the “inner column” (#2) at all times, or with the slip ring contactor (# 23), which picks up the ground signal off the brass ring on the inner column. You can access/inspect that “brush” contactor and the associated brass ring on the inner column from the outside of the column housing.
While you can pull the brass rod out, I don’t believe you can get at that “contact nipple” (#17) and spring (#18) without removing and disassembling the column. The stop button (#8) is holding it all together, and bottom end of the inner column is attached to the u-joint. Again, the brass rod is always in contact with the inner column via that spring loaded nipple (unless it’s broken). Pushing the horn button might move the brass rod a bit, but the contact nipple is already spring loaded against the horn contact pin/rod. The switch is closed by the outer metal ring on the button touching the wheel hub, not by movement of that brass rod.
Makes sense.Probably the contact nipple or the spring. Take another look tomorrow. Thanks DJ
When I pull the brass rod out and then reinsert it, there’s a resistance part way down. I think that’s the pointy end of the rod sliding past the nipple/spring. You might want to try that tomorrow and see if you encounter that spot of resistance. Could be a clue as to the condition of that spring/nipple assembly.
It has no contact resistance. my guess is its probably not there.Let you know after Ive pulled it out. Thanks Dj
Beep Beep!
Turns out the spring that pushes the nipple against the brass rod had corroded.Got a spring out of a ball point pen and cut it to fit. Thanks everyone DJ
Cheapest…fix…ever!
Congrats. Nothing more frustrating than a wonky horn. I remember a few weeks after taking delivery of my car we had a local concourse so I decided to take her up and introduce her and me. I pulled onto the field and turned hard to back into a spot, and hoooooooonk. It wouldn’t shut off. Needless to say everyone stared and I hadn’t a clue what to do. Fortunately someone showed me where the horn hot wire is, and it turned out the PO had just stuck the bare wire in the contact without the conical fastener. It slipped out and shorted against the column, d’oh