'67 L79 horn relay-more problems

[Joseph E.]

Thanks to those who responded with the information necessary to properly wire and re-install the horn relay. I now have another problem-the horns do not work at all even with the aftermarket relay that was working prior to its removal. When the aftermarket relay is installed (with the battery disconnected) and then the battery is connected to provide power, the relay makes a buzzing/humming/clicking sound for a second or two and then stops but the horns do not work. Am I missing something? Is there a problem with the relay, the horn contact in the steering column or possibly the horns? Is there an in-line fusible link that I may be missing that would cause such a problem? I hope some of the members may have some insight as to the cause of the problem otherwise I will start going through the system one part at a time until the problem is found. Thanks in advance for any input.

Joe

#45420

[Jim L.]

Re: '67 L79 horn relay-more problems

Hi Joe

This is a long shot however I recently had what I thought was a good relay. The horns did hum just a little. I opened the lid on the relay and looked through the contact points where I saw dirt particles in between. I used a magnifying glass to inspect (due to old age). I used light compressed air to clean out the particles and the horns worked perfect. Just a possibility. Jim

[Gerard F.]

Re: '67 L79 horn relay-more problems

I think you may have some kind of a mis-connection or grounding problem at the horn relay. If you want to test the horns, just disconnect the green wire at the relay and jump it to the positve battery post. If the horns blow, then the problem is at the relay. Did the replacement relay have the markings as Jack indicated. Jack, where are you?

Jerry Fuccillo
#42179

[Jack H.]

Shakin' it here, boss

Yes, relay should not 'hum' or chatter when you install it. To test the integrity of your horns, remove wires connected to the relay and temporarily jumper the lead wire that runs to the horns (and connects to the 'H' terminal) to battery voltage. The horns ought to blow as long as battery power is connected.

If not, it's time to check the horns themselves. You could have bad ground connection(s) at the horns (they derive ground from being bolted to the rad core support and paint can interfere). Or, the horn(s) themselves could be bad.

The 'humming' you report tells me the relay 'thinks' it sees horn switch contact closure (wiring fault between the horn relay's 'S' terminal and the steering column's horn contact switch). With the horn button NOT being depressed, there shouldn't be contact closure and this could be the wiring harness in the steering column being pinched or faulty.