I've got a '68 deluxe interior with dual horns. Have not worked since I got the car. Previous owner told me it was the relay so I bought a new one. After installing it, the key alarm now works. But, not the horns. So, I tested each directly and found one works and the other doesn't. Nothing at all happens when pressing the horn button on the steering wheel. I've concluded that the issue is somewhere between the steering wheel and the relay, as I would imagine that even with one bad horn, the other would still sound (and I tested the wiring from the relay to the horn already). Nothing obvious wrong with the horn relay wiring to the firewall.
Any thoughts before I remove the steering wheel and inspect the horn button? Am I on the right track? Any common issues?
Hi, We had a similar problem when we purchased our car. When we remove the steering wheel we found that the plastic on the horn contact pin assembly was cracked. If it's cracked Classic Industries sells the kit witch I listed below.
748741 - 1967-72 Horn Contact Pin, Spring And Retainer Set Reproduction of the original GM horn contact pin, spring and retainer to fit the turn signal switch cancel cam on various 1964-72 GM models with or without tilt steering wheel. Reproduced to original factory specifications. Each horn contact pin, spring and retainer set is designed to work with OER part #399294 turn signal cancel cam. Fits various models throughout the GM line
At the base of the steering wheel, there is a crescent plugin cluster of wires. That has all the steering wheel wires. The black is for the horn. test the wire there by apply ground (neg) to it. If it sounds there you will be good to the relay. If not there is a brake there along the way,
If that is good, make sure connection is tight there and try the button. If it don't work, we need to know what type of steering wheel you have so I know what button you have.
Thanks! I'll check the wiring this weekend. Then the horn contact. I have the wood steering wheel with the three silver spokes and silver center with pontiac logo.
Got busy last weekend and couldn't test it further.
But, yes, there is a key-in-ignition buzzer in the relay that sounds like a sick bug of some sort. Once I got that working, I almost wished I hadn't. 😜
Yes, they make an awful sound. Mine was operational but the ignition switch part of the circuit was burned out. Thought it was the relay giving up the ghost when I first heard it.
Got busy last weekend and couldn't test it further.
But, yes, there is a key-in-ignition buzzer in the relay that sounds like a sick bug of some sort. Once I got that working, I almost wished I hadn't. 😜
Yep, As my keys and ignition switch contacts wore down, I learned that I could wiggle the key into a position that would quickly silence the "sick bug".
Taking the lead above, I went to the crescent harness on the steering column to test the black wire and found that the black wired going up the column was pulled out of the harness. Ah-ha, I thought. But when I plugged it in, the horn went on and stayed on until I unplugged it. So, I pulled the steering wheel cap and horn button and the little pin seemed not right for some reason, I pulled it out repositioned everything, plugged the black wire back in again, and put the horn button back on.
Now the unexpected part... in putting it on I pressed the horn button and the horn sounded and stopped like it should...BUT... I felt a small shock on my leg. I looked down and my leg was outside the car, but my calf was barely contacting the rocker panel. Confused, I put my leg more positively on the rocker panel and pushed the horn button. This time I got a good zap on my leg and my finger! Needless to say, I did not try that again and immediately pulled that wire back out of the harness.
What could cause that? The black wire is the ground and power doesn't enter the equation until the relay. I had previously replaced the relay and thought I had it wired correctly, but maybe not? Obviously when the relay was activated with the ground, it somehow charged the whole frame.
My horn on the 1969 never worked everything I did to try to fix this failed , mind you I purchased this car in 1978 I found that there is a wire in the rag joint that does something it may be a ground I’m not sure but after i repaired that wire my horn relay worked at the time I had no horns but when I install the the horns they worked . Let me see if i can find a picture .
According to the wiring diagram, the black wire goes from the horn button to the crescent harness under the dash, out the firewall through the connection block to the relay. My understanding was that this is a ground connection and by closing the ground, the horn relay is activated, sending power to the horns (which are body grounded). But, when I press the horn button, not only are they getting power, but the entire body, too! So, unless I'm way off, either I have something wrong with the horn relay wiring, or there is a point between there and the horns that the wire is shorted against the body. If that us the case, though, why didn't it just blow a fuse? Or, I'm totally misreading the situation (as electrical work is certainly not my forte). All that I know is that with everything connected, if i press the horn and am touching the body, I get zapped!
Pic of my horn relay below.
Edit - in examining my pic and the diagram that bluebird attached, I have the red and black power wires switched, but that should not matter as they are connected and both hot anyway, But... it appears that I have the two plug in wires switched, too (black vs dark green). I'll have to verify tomorrow for sure, but is it possible that somehow by creating a ground link where the power out to the horns should be it is tripping the relay and thus feeding power back to the ground connection, setting off the horns and charging the body momentarily - essentially a short?
Could that mechanical relay be having a problem being upside down? I don't know what the internals look like but maybe contacts could be being closed by gravity. Regardless, the relay could collect water mounted that way.
That is really interesting and a good point (about collecting water). I replaced it exactly like the old one was placed. It is the only way it would go as if I turned it to the way you show it, the screw location would be on the wrong side (the locator pin is on the lehft with the hscrew on the right). Unless someone flipped it upside down and forced a screen through the old locator pin hole. I don't know if that would be related to my issue, but it should be flipped over anyway. I'll try it!
Plus, note that the horn relay also doubles as the key buzzer if the door opens. So perhaps with the door open, key in switch, and the relay upside down, pushing the horn button .........
Thanks for the help. I'm all set. The relay was wired properly so all that I did was flip it over and replace the high note horn (which wasn't working) and it seems fine. They are working and I didn't get zapped (the "test" was a little scary :-) ).
I was at an out-of -town, multi day, show last fall. I came downstairs form the condo to find the horn button(after market steering wheel) on the drivers seat. If you have an aftermarket steering wheel and horn button, you know how screwy the button installation is. Anyway, the horns were not blowing, and I couldn' get them to work. I initially thought that someone heard the horns blowing and pulled the wires at the horns. That was not the case.
I finally got around to trouble shooting. ...had power all the way to the relay (modern relay)...jumped the relay, but no luck. Jumper the horns to battery...both horns were bad. I guess they both "burned out" when the button flew off...? Weird...
Now, to find the correct flasher relay/ buzzer...maybe that's why my emergency flashers don't work...
Last edited by Bronze Bird; 08/12/1810:50 PM. Reason: Because I can
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