Yet Another Horn Gremlin!, Horns not working - group wisdom? Options

[StarBear]

Despite all the postings about horn problems, I have a new one for group wisdom:
1.1974 1.8L; dual horns 335HZ and 400HZ.
2.Original owner (no PO issues!); No long-term storage decay issues – has been is semi-regular use.
3.Horns worked, worked intermittently, then stopped working all together.
4.Horns are OK (tested on direct clip to battery); all other electricals OK; trans ground strap looks OK but haven’t yet cleaned. Cleaned 2 headlight and fuse box grounds.
5.When horn wire touches column ring, the relay clicks (swapped out other known working relays just in case), so connection from horn wire to relay confirmed (so didn’t open steering column to clean inner contacts).
6.Cleaned fuses, fuse contacts and backside fuse connectors.
7.Get only 0.15V across horn hot/ground wires; also across horn hot and ground by headlight.
8.Horn works with hot lead from relay socket 87 (with relay in and ignition on) to horn. Shunt across 30 and 87 gets horn blast, even w/o horn wire touching or ignition on (a clue?).
9.At one time during all the effort, briefly got 12V across the horn wires, but horn didn’t sound (momentary 12V, but insufficient current?).

So… seems like the black/yellow power out wire from relay to horn is the issue. Maybe a loose connection in the relay socket (difficult/expensive to change out, but doable)? or bad black/yellow wire to horn has break (how would one ever rewire that, and how to explain intermittent working)? Anything else possible?

I’m open to group wisdom on this one… (IMG:style_emoticons/default/wacko.gif) (IMG:style_emoticons/default/headbang.gif)

[dr914@autoatlanta.com]

usually if the horns and the relay are good, then it is in the steering column where the butterfly attaches to the wire for the steering wheel rubbing block, and or the finger on the turn signal for the horn comes in contact with the rubbing block. Pretty easy to solve, 914s have GREAT wiring harnesses unless someone butchers them

Despite all the postings about horn problems, I have a new one for group wisdom:
+1974 1.8L; dual horns 335HZ and 400HZ.
+Original owner (no PO issues!); No long-term storage decay issues – has been is semi-regular use.
+Horns worked, worked intermittently, then stopped working all together.
+Horns are OK (tested on direct clip to battery); all other electricals OK; trans ground strap looks OK but haven’t yet cleaned. Cleaned 2 headlight and fuse box grounds.
+When horn wire touches column ring, the relay clicks (swapped out other known working relays just in case), so connection from horn wire to relay confirmed (so didn’t open steering column to clean inner contacts).
+Cleaned fuses, fuse contacts and backside fuse connectors.
+Get only 0.15V across horn hot/ground wires; also across horn hot and ground by headlight.
+Horn works with hot lead from relay socket 87 (with relay in and ignition on) to horn. Shunt across 30 and 87 gets horn blast, even w/o horn wire touching or ignition on (a clue?).
+At one time during all the effort, briefly got 12V across the horn wires, but horn didn’t sound (momentary 12V, but insufficient current?).

So… seems like the black/yellow power out wire from relay to horn is the issue. Maybe a loose connection in the relay socket (difficult/expensive to change out, but doable)? or bad black/yellow wire to horn has break (how would one ever rewire that, and how to explain intermittent working)? Anything else possible?

I’m open to group wisdom on this one… (IMG:style_emoticons/default/wacko.gif) (IMG:style_emoticons/default/headbang.gif)

[StarBear]

OK; will try that. Assumed that since the wire activated the relay OK that the column innerds would be fine, but worth the easy effort. Will update with results.

[StarBear]

George- Yep, tried that but to no avail. Also removed/cleaned the trans ground strap also to no avail. Confounded beyond hope. Might just shunt a wire between the relay power out plug and the B/Y wire, hoping that maybe it is the connection at the relay connector.
Meanwhile, I did notice your entry in the 914 Tips book (one of my two "go to" resources, along with Haynes) about the stall/restart issue involving the dual relay under the battery tray - installed a new one and hope to check it out soon!

[StarBear]

Took time and patience, but solved it:
My fuse relay board is not laid out like virtually every manual and forum description, indicating the horn relay is on the far left, by drivers side door. Mine is second from the right, as shown in a hand sketch on Bowlsby (914 Tech Notebook).
I heard the relay clicking and usually that's an indication that the relay is OK, but did wire diagnosis on the relay the manuals say is the horn relay. All was OK.
Tonight I actually FELT the relay and found that one wasn't clicking - it was the second to the right, which has the correct wire color scheme. Replaced it. HONK HONK HONK.

[StarBear]

George - solved it! See new entry. Relay was clicking, but guessed something not working right, so replaced it anyway. HONK HONK!

[Tbrown4x4]

Relay clicking only means the coil side had power and ground. The contacts can burn and not work properly.


Glad you solved it. I had to rebuild both horns and the low tone still isn't right.

[StarBear]

Relay clicking only means the coil side had power and ground. The contacts can burn and not work properly.


Glad you solved it. I had to rebuild both horns and the low tone still isn't right.

I've read (but not done) that the horns can be tuned through the little black panel on the back. During my adventure I found the little white grommets inside the horn mounting bracket are very important - they isolate the horn from the body. Also cleared/cleaned all the end wires and replaced the terminal clips. Ought to be good for another 45 years...

[Tbrown4x4]

There is a screw under a gob of sealer you can turn to change the spring tension of the points inside.