Horn Button Adjustment?

ryanheacox

ryanheacox

Well-known member
I was going through the list of small things to do to get my car ready for another season when I remembered that I had a problem with the horn button.

During regular daytime driving, it works probably 90% of the time, I'm sure there's a little corrosion in there and I can clean that up pretty easily.

However, after turning the headlights on, the horn stops working. Sometimes, I could get it to work intermittently if I jiggled the light switch, but not reliably. I've gone for the horn a couple of times at night and it hasn't been there when I needed it...

Is there some sort of adjustment that I can make? It seems to me that the button just isn't making contact when the lights are on.
 
Have you removed the light sw assy at the bottom of the steering column and ck'd for oil and/or corrosion on the contact surfaces??
Paul in CT
 
Modern day production light switch? Modern day production switch rod?

Properly matched switch rod to the length of your steering column?

Good ground between steering column and the car frame itself?

All questions that come to mind.

The modern light switches are notorious for not having enough tension/contact. Usually evidenced in turning of the steering wheel resulting in turning of the light switch, but can be a matter of just "losing" the headlights altogether.

Or the horn.

The light switch control rods HAVE to be matched to their corresponding columns: a couple of these are quite close, particularly in the 30-31 model years. Suggest you identify your column specifically and check the service bulletins to be sure you have the right length light switch control rod to match.

A rebuilt steering column can cause this. Positioning the steering worm (not easy but rebuilders do this) can make the column a different "length" and lead to what you're describing. The steering wheel might end up a little "closer" to the driver - but not noticeably so - but enough to create a poor contact at the switch.

I expect it might be possible to build up the bottom contact of the light switch control rod with solder or even a small self tapping screw to be sure of contact? But maybe check some of these other possibilities first?

Or maybe even a good clean out...to include re-establishing the ground between steering box and frame (The horn is one of the few Model A "utilities" that are continuously energized and you "ground" the circuit with the horn button to complete the circuit and sound the horn.)

Joe K
 
First and foremost, you have to make sure there are good connections to ground for the horn button and the horn. Too many places that can and will get a coating of paint that will insulate the metal parts preventing a good ground. Once you have the grounds and wires sorted then you need to look at the button. The button I think can harbor a lot potential for poor horn operation.

I took apart a bunch of horn buttons recently and was astonished with what I found.

The back side of the button is a steel disk. In the center it contacts a brass button that is crimped on the end of a wire. The ground was the spring that pushed the button up. Yes, I also found the steel disk to be rusty in a couple of cases. Mostly there were problems with corrosion at the contact point that really needed cleaning.

So you have several places for dirt and corrosion to cause contact problems.

I also found the horn area to be gummed up with crap. Figure on how many decades of spilled drinks. Just getting the retaining ring loose was interesting. Found a couple needed a light heat to loosen the what I believe to be a sugary mess. Then you get the Aluminum corrosion from the goop that swelled and cause problems.

In two cases the spring had been overheated from too much current (short circuit) and lost its spring.

So you have a lot of potential things wrong giving you a poor connection at the horn button. I suggest that you measure the resistance of the button to ground. I have to warn you that getting the button off looks simple but can be a delicate pain in the butt. One wrong move and the tab falls off.

After what I saw I would say there have to be a lot of poor sounding horns because of a poor horn button switch. I believe the risk of taking a horn button apart may be worth it to ensure good operation of a signature feature of the A.
 
Your lights are taking some of the current that could have gone to the horn. Start with the easy stuff first. Remove the horn cover and polish the commutator. Just hole some fine sandpaper against the commutator while the horn blows, then put a few drops of oil on each of the two felts for the armature. Reinstall the cover and try the horn with the engine at fast idle and the lights on. If it still doesn't blow as it should just loosen the horn adjustment screw one click and try it again. It might even need two clicks. Let us know if this helps.
 
I had similar troubles with mine. After taking it apart and cleaning, adjusting, cleaning re-adjusting multiple times I bought a kit to replace the horn wire through the light switch tube. At first the wire looked good when I removed it but then I gave it a bit of a tug and the wire pulled right out of the top soldered connection. Even though it looked good the original connection had gone bad. Replaced the wire and now it works like a champ.
 
I cleaned and oiled the horn at the beginning of last years operating season. I think the horn sounds pretty good, whether the lights are on or not. My problem is that 9 times out of 10, the horn won't sound with the light switch in the on position unless it's on the high beam position and I fiddle with it.

The more I read, the more it sounds like there's more corrosion/rust/gunk in the switch body than I had first thought. I'll have to check when I go home in March.

This is what the horn sounds like, I think it sounds better than a lot of sick sounding ones that I've heard, but you tell me.
http://www.youtube.com/watch?v=O7Q3KbvZ910
 
I had a very similar situation. My horn was intermittent, would work until I turned lights, on, etc... After checking contacts, removing horn rod, checking amperage, etc..., I discovered that the light switch body was not probably engaging (the contacts). I played with it quite a bit, but ultimately just made sure it was in exactly the right position when I set the bail and everything has worked perfectly ever since.
 
Thanks. It'll probably just take some fiddling with but I wasn't sure if there was something specific that I could adjust. I'll have to report back in a few weeks with what I find.
 
1931 flamingo said:
Have you removed the light sw assy at the bottom of the steering column and ck'd for oil and/or corrosion on the contact surfaces??
Paul in CT
Click to expand...

Today I removed and cleaned out the light switch assembly at the bottom of the steering column. It was full of gunky grease/oil.. It was nasty to say the least. Now my horn works all the time. It also fixed the high beams issue. :)
 
If you use a later lower plate with the tube up the shaft it cures the gunk problem ---I don't know about the repros quality, with both home made ones and original i have soldered the tube to the plate so there was not even seepage around the crimp, I don't know how mine looks inside, havn't taken it apart in 30 years, never a problem ---and the sterering gear stays full longer.

I do have a 2 tone horn, pushing the top of the button makes different contact than the bottom,
 
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