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When I press the horn button, I do not hear a relay click. The stop/hazard lights work, I understand the horn is on the same fuse, so the relay/horn should have power. I did find the horns up in the front fenders and was able to undo the connector of the green wire on one of them from the top.
I expected the green wire to only have +12V when the horn button is depressed. Instead, when I put a test light (actually DVOM with sound indicator for continuity) between the green wire and ground (headlight actuator body), I have continuity. Am I right to assume that this is not as designed?
What might be the reason for this, sticking relais or bad horn button assembly? If so, both horns must be bad, otherwise they should be blowing continiously, right?
I tried to find the relay under the dash, was told it was a black box, 1x1x1". All I could locate was a yellow box, pls see pic. Is this the horn relay?
lets see if i can help. I have an 81 vette same issues, so this past winter I decided to tackle it, the first thing i did was find the green wire, shaved a little wire coating off had wife push the horn button no power, so I ordered a kit that had all the steering coloum parts for the horn plus a new horn button. I found a diagram from WILCOX corvette on how to test the horn. some horns came with a yellow relay most with a black relay. the first thing i did was install a new relay, still no horn. so i carefully removed all the horn parts be careful wat makes the horn work is a spring and small rod that when you press on the horn it makes ground that is what makes the horn honk. once all this is apart you can stick a phillips screw driver into the hole and ground it my horn than blew. when i reassembled every thing the horn did not work. what the heck took every thing apart and found out the L bracket wasent grounding, so i bent it slightly walla it worked. I see you live in florida i live 20 miles east of pensacola
I tried crossing the part number 25505674 and it did come up as a 3 terminal Horn Relay.
Remove it and see if there enough exposed wires to tell what colors they are at the harness pigtail.
I know you have a 1982 but the wire colors should be the same as on a 1980 Orange, Black & Dk.Green
Do a continuity check between the black of the 3 wire connector and a good known ground. You should have continuity when the horn button is pressed.
Grounding the horn button is what energizes the horn relay coil.
This is a doctored 1977 drawing with 1980 wire and circuit numbers added.
Hope this helps.
Went back to the car and found out the following: the horn(s?) work, at least the left one as I touched this one with a jumper wire from the battery. The green wire from the relay to the horn is good as I removed the relay and jumpered the red to the green wire in the relay connector and the horn blew.This also means I have +12V on the red/orange wire to the relay, of course. Once the relay was out I put +12V from the battery to it and connect it´s ground terminal to the body of the car. The relay clicks, so relay is good, too.
When I took off the horn button, I found the rod out of it's hole, somewhere in the steering wheel hub.
All parts are there, the spring, the little plastic sleeve for the rod, the spring part with the three plastic rivets still intact, the L-shaped lever and the three spacers. I cleaned all up and re-installed it, yet no horn. I grounded with a screwdriver, no horn. I jumpered +12V to a testlight, touched the ground pin in the relay connector and pushed the horn button - no test light.
This brings me to the conclusion that the ground from the horn button down the steering column to the relay connector is bad.
Do I have to pull the steering column to check?!? I hate to mess in the footwell of C3s as all is small and tight down there.
Last edited by colonel328; Jun 30, 2022 at 06:54 AM.
One more thought: is the length of the rod in the hole with the little spring crucial for the horn to blow? I think mine could have been trimmed as I remember it being only 1/2" or so long and I believe they are about 1" long when they come new.
Does the rod needs to touch the bottom of the hole or does it ground through the windings of the coil spring?
First place I would check is the ground path from the horn button to terminal G of C144 (C=Connector) C144 is the Harmonica Connector from the column harness to the main dash harness.
Your connector will have additional wires because of the cornering lights.
One more thought: is the length of the rod in the hole with the little spring crucial for the horn to blow? I think mine could have been trimmed as I remember it being only 1/2" or so long and I believe they are about 1" long when they come new.
Does the rod needs to touch the bottom of the hole or does it ground through the windings of the coil spring?
the spring as well as the side of the rod making contact in the hole should be enough as long as surfaces are clean... I recently had to repair my uncles 76 vette since he let someone swap his steering wheel and they lost all this stuff. I used a spring from a ball point pen since we were in a pinch and it needed the state inspection the following day.
Without pulling the T/S switch at least partially out you are only going to see the front side of the switch.
Yes, "G" circuit #28 wire is connected and pressed into the plastic of the turn signal switch via contact bridge terminal.
You can see in the photo below the copper spring button contact.
The Yellow arrow points to one side of contact bridge.
That is "G" or circuit #28
Now if you remove the switch you can see where "G" circuit #28 black wire runs to the contact bridge.
The wires on my connector look are bit different, but I guess the marked on in the picture is "G":
The wire colors will be different as my photo above is from a 77 T&T column.
There is a 1st and 2nd design T/S switch.
1st design 1976 through early 1979 used GM #1997983
2nd design Late 1979 - 1982 used GM #1997984
You can use a 1997984 on a 1976 through early 1979, only difference is "F" and "E" wire colors will be different and will include extra wires for the cornering lights.
Went to work on the car again. The good news is: the horns blow. The bad news is: I have no idea why.
I measured continuity between the coil spring in the hub and pin G. DVM didn´t sound. Ok, pinched wire or contact in the coloumn. I jumpered the spring to pin G, horns didn´t blow. What? I measured continuity from G to the black wire/ground pin on the relay and it´s there. Hm, ok. I jumpered pin G to a good ground and the horns blow. Jumpered back to the steering wheel contact, nothing. Jumpered the spring to ground, horn blows.
I got frustrated and put the horn button mecanism back together in the hub after I used some sandpaper on the retainer. I must have touched the metal rings with a screwdriver during installation and the damned horns started to blow. Tried to press the retainer in the various directions and horns blew - not always and not in every direction I pressed the button, but each time a little more.
Don´t know what happened, but as of now, I can live with that. I will continue to watch horn operation, of course.
Hi guys. I haven't been on here in so long my username didn't work anymore. I was fixin to make a post about my 1967 Coupe (that I've owned for 54 years, BTW ) having a problem in my ammeter that I believe is related to the horn relay. My horn wasn't working so I decided to investigate the cause. I started at the horns and determined that they worked properly, then moved back to the horn relay. I pulled it out and determined that it too was working properly on the bench. That led me to the horn button in the steering wheel. I found that there was no ground available for the horn button to find. Using an ohm meter I checked for continuity from a jumper wire attached to the negative post of the battery to the steering shaft at the nut and found no continuity, and then down the shaft to the upper coupler on the shaft at the steering box. Still no continuity to ground. Checking at the steering box itself I found continuity. That meant the continuity was lost between the lower and upper couplers.
As it turns out there is a rather "Rube Goldberg" spring that is supposed to make a connection between the lower and upper couplers. It had lost continuity at the pin in the lower coupler that holds it in place. It's hard to imagine that oxidation has occurred between the pin and the steel of the coupler, but that is apparently what happened.
The proper fix will be to take the couplers out and rebuild the lower one, but that involves taking the steering column out to get at the couplers. I temporarily added a jumper wire between the lower and upper couplers and it solved the problem. A kit is available from Zip Corvette ( https://www.zip-corvette.com/67-69-s...build-kit.html) as seen in the picture below. That goofy spring is in the upper left hand corner of the picture.
This may be the problem that the originator of this thread is having.
Now back to my post about the horn relay / ammeter
1982 horn doesn´t work
) having a problem in my ammeter that I believe is related to the horn relay. My horn wasn't working so I decided to investigate the cause. I started at the horns and determined that they worked properly, then moved back to the horn relay. I pulled it out and determined that it too was working properly on the bench. That led me to the horn button in the steering wheel. I found that there was no ground available for the horn button to find. Using an ohm meter I checked for continuity from a jumper wire attached to the negative post of the battery to the steering shaft at the nut and found no continuity, and then down the shaft to the upper coupler on the shaft at the steering box. Still no continuity to ground. Checking at the steering box itself I found continuity. That meant the continuity was lost between the lower and upper couplers.