Horn issue...

[Abodysrule]

My horn worked fine. Then I swapped engines. Then the horn didn't work. I can hear the relay clicking, but no horn. I checked the ground by putting power directly to the horn wire, horn works, that's good. Installed a new relay, horn works. Two days later, same issue. I can hear the relay clicking, but no horn. Can I be killing the relay somehow? Anyone ever had this issue? Outcome?

Brian

 

[Dana67Dart]

More likely bad connections.

What car
What year
What wiring changes

 

[Abodysrule]

'67 dart 2 dr hardtop
I didn't make any wiring changes for the swap, except: different ignition coil.

Is the relay supposed to be grounded to the chassis? Maybe I can check that connection.

 

[barracudadave67]

Check the wires in your bulkhead connector. You might have bumped/disturbed some of the wires, in it. Trace the horn wires back to it and jiggle them.
Bulkhead connectors are a known trouble source.

Dave

 

[Mattax]

Diagnoses methodolgy is same as before.

Horn is power is joined to the main circuit at the alternator.
IF the battery is charged and in good condition, then the connection or wiring has too much resistance for the higher current needed to run the horns.

Update, the horn works, it was indeed the relay, just a coincidence.

I can't recall for sure but thought there was a photo from your car with a hacked up harness at the alternator.

 

[Abodysrule]

I'm not sure what a "hacked up" harness constitutes, but my wiring is new and I make every attempt to make clean and durable connections. The relay is getting power directly from the alternator lug, the horns are well grounded. Disparaging comments are not helpful.

I connected the first blade on the relay (that the horn switch wire goes to) to ground and the horn works. Then I reconnected that blade to the relay and touched the horn wire at the column (that comes from the bulkhead connection) to ground and it works. Thus, it is the steering column ground that is the issue.

Thanks everyone, I can take it from here.

brian

 

[Dana67Dart]

Disparaging comments are not helpful

I don't think Mattax was being disparaging. I think he was saying that like many of our cars previous owners have worked their magic on our cars and we have to undo the magic the POs have done.

I am sure he was not suggesting that you did any hack job work on your wiring.

 

[Mattax]

Egzactly. There was a thread I responded to with a harness in the photo that had tape around the R6 and H1 wires indicating rework or splicing. I could not recall if it was yours but it was also a '67. Hence "I can't recall for sure"

 

[67Dart273]

I have never known, EVER for Mattox, unlike myself, to make a disparaging comment. Don't take things so personal. Ask yourself, "How old, again, are these cars?" There may be "hacked" wiring in your car that you have not seen or detected yet. Or, it may be a connector problem. For example, in the later cars, the horn relay is INSIDE the pass compartment, meaning, the full horn current must flow through a terminal in the bulkhead connector, and THAT alone can cause this disfunction.

Some things to check. Make CERTAIN the horn is staying grounded. Rust around the mounting bolt

You might adjust the horn(s) purposely. That is because the buzzer contacts can become rusty/ corroded, as well as the the screw threads, and the act of adjusting them while sounding, will sort of burn them clean. "Mark" / note the position before you turn it, so you can rough it back into shape

Horn relay does not need ground. The path for the coil is from the battery terminal on the relay, through the coil, to the horn button, and ground.

The contact of course is batter, through contacts, and to horn.

Be sure the horn flag/ push on terminals are not corroded and go on tightly. Might "work" them on/ off several times

 

[Abodysrule]

OK, my bad Mattax. It was the ground on the column, horn is working fine and consistently. I used an ohm meter to measure and although there was sufficient current passing to make the relay click, it wasn't enough to make function properly.

 

[67Dart273]

Hmmm that is interesting.

 

[Mattax]

I'm not sure I follow the what was checked with the ohmmeter. Sheet metal (dashborad) to column?
It does go to something 67dart273 frequently points out - an ohmmeter is only good for identifying breaks and really poor connections and wires.

The '67 cars (and probably many others) had a ground wire for the column on the upper attaching bolts.

Since replacing the relay fixed the problem temporarily, maybe what happened is there is oxidation/ corrosion on several of the connections.

 

[Mattax]

Here's one - not my car but looks the same on my 67

 

[Abodysrule]

Yeah, I have that ground wire on the column. I jumped the horn wire to that and the horn sounded. No problem there.

It turns out, by checking with the ohm meter on various places, I found that the steering rod's bottom portion (going into the steering box) was fully grounded, but the top portion (collapsible column, so two part steering rod) was not sufficiently grounded. I checked this by removing the steering wheel and grounding the horn wire to the chassis, for example, to the shift lever on the column. That closed the circuit and the horn sounded. But, when I checked the connection between the horn wire and the top portion of the steering rod (where the steering wheel nut is), there was resistance indicated by the ohm meter. Indeed, when I jumped these two points the horn didn't work.

I forgot that I had done some work on the steering column during the engine swap (I'm getting older...). Specifically I had changed from the pot coupler to a Borgeson steering U-joint. Long story short, I swapped out the '67 steering rod for a '68 unit. The '67 had a metal clip that electrically connected the top portion of the steering rod to the bottom portion, while the '68 shaft had no clip. I believe therefore that is why the top portion of the new ('68) shaft was not properly grounded. I did note that jumping the horn wire to the retaining clip that holds the bearing at the top of the steering rod, the horn sounded. So, I installed a wire, between two screws that secure the retaining clip for the steering shaft upper bearing, and that rubs against the steering rod. The (rather stiff) wire rubs against the steering rod and secures the ground. I used dielectric grease on the wire/column in that area so it won't wear over time.

I have no doubt there is a better way, but this was expedient, creates a good ground for the horn, doesn't interfere with anything and will be long-lasting.

Brian