Horn - simple test ?

[Jim Clement]

with the two wires that exit the steering column .. if i touch one to ground.. should the horn not sound ?
and .. the other flash the lights ??
when I touch either of these to ground.. or each other.. nothing??
any thoughts ?

[Mike Wilson]

Check: fuses and contacts on the steering column. Can you hear the relays click when you touch ground?

[Jim Clement]

all fuses are new.. and appear good..
I cannot hear any click .. but will go and give that a try..

if I use a tester .. and touch one end to the column wire and one to ground.. should there be current .. ie the test light come on ??

[Mike Wilson]

I hope that someone more knowledgeable will weigh in but, I don't think the test light will illuminate as you are competing a ground. There isn't any current in a ground. Right, Guys?

Did you check the spring-loaded contacts on the steering column? Were the horns working before? How about the ground strap in the steering coupler?

[Jim Clement]

yes..
spring-loaded contacts are new and appear to be working correctly.. and the ground strap is new and extra clean..

[Mike Wilson]

Can you provide power and a ground to either horn to see if they work? That will eliminate one variable. Then backtrack to the relay.

[John Brooks]

There is TWO power circuits used in the relay. One is through the relay coil to ground in the wheel (that's the wire you are playing with). The other goes to a normally open contact in the relay. When you short the wire at the wheel to ground, the coil closes a contact, that power goes to the horn and then to ground.

So you can be missing either one of the voltages, either there is no power to close the coil, or if it clicks and closes the contact, power goes to the horn, that power can be missing.

You need a multimeter, or a test lamp. Check for power on the input side of the relay for both voltages. One voltage to the coil and one for the switched contacts. If both voltages there ground the coil side and see if the relay clicks when grounded. If it does see if you get a voltage appears on th switched contact side when the coil is grounded.

If this works. Then you get to chase the wire harness and see if the voltage appears at the horn end.

You can put a test lamp on the steering wheel wire and to ground. If the light comes on probably the coil is good. Same for the relay to horn wire. If the light comes on when the relay closes the relay is working. Here is a simple drawing

[Mike Wilson]

Thanks, John. I'm adding your knowledge to my data bank.

[Greg Bryan]

Jim - what colors are the wires sticking out of the steering column at the steering wheel ...

[Jim Clement]

both wires are brown .. with a hard connection ending.
I did a continuity test on both.. between then ground strap on the steering column and the steering wires.. one showed continuity..one did not..
I also checked the continuity between the steering column and the ground.. good there..
so tomorrow will start to check the power supply and the relay..
does that make sense ?

[Mike Wilson]

Makes sense to me but I'm a rank amateur compared to Greg and John. I'd check to see why you don't have continuity on the one wire. How about continuity between the protruding wires and the contacts on the column?

[Greg Bryan]

Jim - since your car is a '57, I'm sure you know there was a change to a lot of things midway through the model year, including the wire harnesses. So your car will be wired like the T1 cars or the T2 cars depending on when the car was built.

If those are beehive taillights, it may be wired like the T1

If it's a later '57, it will be wired like the T2.
I heard a rumor that there is not a real clear ViN break where the wire harness change took place, so some late T1s may be wired like the T2.

The light flash feature on the T1 and T2 cars flashed both the high and low together. T5 and later cars have the relay that is shown above that will flash only the high or low beams depending on the position of the light switch.

I don't think either of the wires in your steer shaft should have continuity to the ground strap by the steering coupler. Those wires are soldered to the slip rings which are insulated from the steering shaft. Basically, to either blow the horn or flash the lights, the wires are grounded to the shaft (hence the importance of the ground strap) by the horn ring or the light flash button. You should have continuity from the end of the wire to the respective slip ring.

[John Brooks]

Jim

Yes both wires are brown, because they are both relay grounds. Now you need a multi meter, check the conductive path(brown wire) from the steering wheel to the relay brown wire. You must remove the relay screw and isolate the wire so it will not pick up a parallel ground. The one wire that reads shorted to the brown wire on the relay ( the relay with the black and yellow wires) goes to the horn. You can verity it by reading from the horn end, back to the relay on the black yellow wire. The brown horn wire is also a ground.

Anyway as shown on the wiring diagram from Greg, one brown wire goes to the horn relay, the other goes to the autobahn flasher. The relay with the black and yellow wires is to the horn, the light relay has yellow wire out.

It's been 50 years since I had or worked on a T1, but if I remember the relays are under the dash and easy to access. if you hook it up backwards, the center button will blow and the horn ring flash the lights.

[Jim Clement]

so..
I checked for power on the red wire.. yes.. power is there.. confirmed by test light
then jumpered the power to the horn wires.. nothing..
then checked the continuity between the relay and the horn using my muti-meter long extension.. good..
then checked horn function on 6 v battery.. works well
then checked the ground wire at the horn.. for continuity with ground.. good..
and checked continuity between the horn contact wire at the steering wheel and the relay.. all good..
what am I missing..

[John Brooks]

Meter through the spades on the horn it's self . They should be shorted. Then jump 6v from the battery to the horn, see if it blows. Now this is battery to ground so just swipe the wire fast on the spade. If you get a big current surge or a HUM the contacts are stuck. If no blow the contacts in the horn are open or corroded. Some time you can smack it and it will free up.

The horn contacts (look like the points contacts) also go through a coil, when it sees a current flow, produces a magnet force, it pulls the horn diaphragm and momentarily open the contacts, spring load on the diaphragm returns the contacts to the closed position, magnet again, then it opens again. This on and off cycle is what causes the vibrations and causes the noise. The spring load on the diaphragm determines the tone.

If you have good power to the relay and a good ground in the steering wheel, when you ground the wire you should hear the relay click. Now the wire you see comes from the slip ring so be sure you have a conductive path from the relay to the wheel (Brown wire) you can hear it click you should see 6v out of the relay to the horn. If you have the meter or test light on the black/ yellow Wire on the horn, it should light up or the meter should show 6v when the brown wire is grounded to the wheel. One lead + on the black wire the other - on the brown wire spade

try a Jumper wires from battery to the horn. What you have described is a functioning logic circuits and relays. Your horn contacts are stuck. You can take it apart, clean the points in the horn and put it back together. It's pretty simple inside. Horns don't care about polarity, two spades one hot, one ground. Hook it up backwards It sucks just as loud as it blows when wired properly.