1935 horn wiring issue

R

Ron35

Member
Although I read 2 similar threads, I'm still stuck with 2 non-working '35 horns so here goes. Background:
1. they worked poorly but worked a few months ago but then stopped and didn't respond to adjustments with the screw adjuster, and now not at all.

2. They are repro horns, judging by prior posts and a picture in the Forum; not sure where/when purchased. I'm assuming the horn itself grounds the horn?

3. I took apart both horns and cleaned what appeared to be the points then reassembled each so again the adjusting screw is directly above.

4. both horns have 6.3 volts on BOTH wires attached to each horn. Each has a yellow and a blue/yellow wire attached to the horn. the yellow is also attached to the ignition starter switch (hot side); the return wire for each goes into the light switch basket. I've taken that apart and cleaned each. The basket was making a snug fit. The bail wire came over snug seemed to fit correctly. W. volt meter, no volts showing when touching the horn rod, etc. but the lights work.

5. Some earlier posts talk about using a relay but others disagree. I don't think I have a relay in the circuit. And in any even it all worked earlier.

6. Wife pushing horn button has no effect on voltage reading

7. pushing the horn button "feels" like there's a working spring.

Any thoughts? Thanks, Ron
 
Ron, If your horns are originals then there should be two wires into each horn. The yellow wire is power (battery negative ) all the time and connects to the battery side of the foot starter switch and not the starter cable side. The blue with yellow wire goes to the centre contact in the headlight switch where it contacts with the horn rod centre contact and that is grounded when the horn button is pressed. You should not be testing for voltage here as it is a ground connection and not power which is battery negative, assuming your car is positive to ground as original. You mention an ignition starter switch does this mean you don't have a foot starter any more ? I would suggest that you do any voltage testing with a test light and not a voltmeter which may be confusing your readings. Some reproduction horns only had one power wire into them which requires a relay to be fitted so that the grounding horn button circuit will operate the power to the horns. Those horns received their ground through their metal mountings. If your horns are original set up with two wires into each horn then a relay is not required. By this time I would expect all the contact settings and armature air gap settings are incorrect because you have done adjustments. These settings have to be fairly correct for your horns to work well. A good photos of the internals of your horns would be beneficial here. Maybe you could remove the horns from the car and operate on them on your work bench powered directly to a 6 volt battery . A test you can do is connect a test light across both terminals of a horn and then press the horn button and the light should come ON. Regards, Kevin.
 
Hi Kevin: Thanks for your prompt reply and advise. Let me clarify: My horns are not originals based on some photos in the Forum. I have a foot starter. My horns have the 2 wires going into them as described above so it looks like I don't need to worry about a relay. So the plan is:

(1) I'll remove the horns and take and post photos.
(2) I'll use my test light and report back
(3) I'll eventually need the contact settings and armature air gap settings. I'll hold off on doing the settings until I first use the test light and report back.

Ron
 
Original horns are very touchy as to adjustment. Sand the points with 400 grit paper just like ignition points. I bet they would work if you adjusted them where you could see the points open and then very gradually turned the adjustment screw closed until they beeped. You don't have to turn the adjustment screw much to get them to beep/not beep. That is what I did on my 36 and 41 horns to get them to work after puzzling over them not working.
 
Hi MRTexas: I'm pretty sure my horns are reproductions; photos soon. I did clean the points with grit paper like ignition points and then tried to find the correct gap--do you know if a precise gap number is advised, as with spark plug gaps?
 
Here is an original 36 with bracket for the right side. Did not install since I use an ahooga horn instead to amaze the kids. The way these horns work is a contact swings(vibrates, bounces) from one contact to the other. The adjustment is very touchy. Took some time to get mine right. No precise gap number. You adjust until it beeps!

36806680814_2c8a845e0f_b.jpg36h1
37485552332_cde07448d9_b.jpg36h2
 
Use a ground wire to the earth terminal (Blue ) to say a clean contact like a head bolt ,this should activate the horn then you can tune the point setting for the best sound .Remove the light switch and do the same after that to the contact in the centre of the light switch that contacts the steering rod ,this to should activate the horn also ,if it does it tells you that the connections for there are ok and the horn rod is not working ,Ted
 
Thanks Ted: I'll try that after I reassemble the horns. On Inspection I noted one set of points off center from each other so not sure the spark could occur; I reset them. And I noted the fixed post which holds one end of the plate that suspends the upper part of the points was rather loose; could be a sufficiently loose connection to partly explain what's going on. (ps are you the member who came up with the modified floaters? If so I may be a customer down the road)
 
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