Horn(y) issue

[BlazerRico]

I just bought a 85 K5 Blazer and have lots of questions. The current one involved the horn. The stock horn doesn't work when I push the center of the steering wheel. I figured the entire horn was bad and was surprised when installing a new ignition cylinder. While doing this, I shorted out the metal plunger (located at about the 2 o'clock position on the turn signal assembly) against the center shaft of the steering wheel. To my surprise, the horn sounded. I experimented and found I could short out the same plunger to the center shaft using the lock plate. I was hoping this is the actual mechanism the horn uses. However, when I reassembled the steering column including the spring, lock plate the horn wouldn't sound.

Can anyone provide any insight?

My next step is to clean the brass attached to the plastic insert with the shaft that goes through the lock plate. I am thinking perhaps it is used to make a connection because of the ring of brass. I haven't succeeded in having this piece complete the circuit yet. I don't know if that is the correct way to get this working.

Thanks for any insight.

 

[K85 Octane]

All the horn stuff in the column is used to make a ground. That ground feeds the relay under the dash which then supplies 12+ to the horns. Make sure that the horn button is working right. All the stuff below it is there to KEEP contact with the horn button. So the ring should always be touching the spring loaded plunger. Its the horn button itself that makes the ground connection complete. Try to find a column rebuild thread that shows the horn set up, or google it, and make sure you arent missing pieces.

 

[82355]

Take pictures of what you are working with.

Martin

 

[BlazerRico]

I think I figured out the issue.

Here are the turn signal cam, the cover for the horn and the plastic to which the cover attaches. There is obviously a large amount of rust on the horn button. I think this is, as well as the broken turn signal cam, are the issue.

The cover backing (the gray part below) has a wire with a spring and a shaft which locks into the turn signal cam. The connection between this wire and the cover is corroded. There is no electrical continuity between the end of the wire and the metal spring visible below.

I suspect that the metal spring connects with the steering shaft. Since there is no continuity, the circuit cannot complete and the horn cannot sound. I am going to try to find the parts to reassemble the steering wheel and test my theory.

Here is where the turn signal cam is broken. This causes the small shaft which compresses the spring up against the small metal tab in the cam to not connect so it cannot complete the signal.

Here is the back side of the horn button. Note the abundance of corrosion. There are two metal plates and there is no continuity between the plates. The outer plate has a connection for the wire which connects to the turn signal cam. The inner plate has the spring steel which I suspect connects to the steering shaft. The lack of continuity is what I suspect is causing my horn to not work.

 

[BlazerRico]

After some more time with the voltmeter, I am pretty certain that there shouldn't be continuity between the spring which touches the steering shaft and the wire clipped to the horn button. I am thinking that the horn button has two layers of metal which when pressed together complete the circuit and sound the horn. I am unable to test this on my horn button because the corrosion currently prevents my from actually making a continuous circuit.

 

[MEANSTREAK K30]

Does your turn signal when turning left not cancel out by itself?

 

[BlazerRico]

I fixed the issue. It was the corroded horn button.

I took the button apart by popping the plastic rivets off the of the outer plate. I then soaked them in vinegar over night and scrubbed them after. I then glued the assembly back together. I tested continuity when the plates are pressed together and found it to be there.

I reinstalled the reassembled horn button in my Blazer and I know have a functioning stock horn again.

Thanks for the input before everyone.