The horn on my ‘66 is not working.The car was restored and was driven 1,800 miles in 22 years so I don’t know what that might have done to the relay.How would you test the relay with a multimeter without removing it?12 volts in red wire.

 

Put 12 volts to the horn it self

 

Over 20+ years and little usage, moisture can corrode the relay contacts. Depends on what amount of moisture the car was exposed to during all that time.

It's just as likely the horn button contact on the steering column needs to be checked. You can do that with a multimeter. Check for zero ohms when the horn button is pushed. If you don't get zero ohms, you'll have to go through the horn button circuit starting at the "harmonica" connector to the turn signal switch. Pull the connector and check for zero ohms when the horn button is pushed on the back wire at the column side of the connector. Then try using a test lead to ground the black wire on the dashboard side of the same connector. If the horn doesn't work then, you'll have to check the circuit at the firewall connector. Look at a wiring diagram for the correct pin on the firewall side of the connector.

If the horn button is good, check the relay with a test lead connected to the relay terminal that had the black wire connected to it. Ground the other end of the test lead. If the horn works, you are good to go.

If the horn doesn't work when you ground the test lead, use your multimeter to check for 12v at the terminal where the green horn wire connects when you ground the test lead connected to the black wire terminal. No voltage, you have a bad horn relay. It might be better to use a 12v test light rather than your multimeter for that test. Multimeters are generally very high input impedance and may show voltage even with bad internal contacts on the relay.

 

Easy test. Hold your hand on the horn relay have someone press the horn button. If you feel the click and the horns don't blow, your horns are not working. If you don't feel click the black wire under the cap on the steering wheel is not grounding when you push it below the horn. The horn relay winding could be open, but that's certainly not likely.

 

Also make sure the black wire and the green wire are attached in the connectors that are part of the Horn relay to the side not the ones at the red wires,, but on the side of the horn relay, the black and green have to be plugged in.

 

The horns work when you put 12 volts on them.

 

take the horn cap off and then take a screwdriver and ground the plunger to the steering wheel

 

I used a screwdriver to depress the horn button and grounded it on the large nut and the horns worked.I put the contact ring back on and it worked.
The only thing that I can think of is I disconnected the horns before I put the 12 volts on them and then reconnected them.Anyway,they are working now.I may have mentioned it before but this car was frame off restored in 2003 and had 1,800 miles on it when I bought it in 2024.The horn probably didn’t get a lot of use during those 21 years.
Thanks for all of your help.

 

The horn does not work again.It came back and was working but this morning it wasn’t.Is it possible the relay is bad?It is a 20 plus year old reproduction relay that probably hardly got used.Can you remove it and clean up the contacts or do you just buy a new one?

 

Start at the horn contact behind the horn button.

 

Take a fine metal sand paper and run it thru the contacts under the horn button.

 

How do you get to them?

 

take the cover off

 

If you had someone to help you have them press on the horn button while you feel the horn relay cover by the radiator support , if you can feel a clicking noise your problem is in your wiring from the relay to horns or horn problem
Bob

 

I'll bet its in the column or just the horn contact

 

Clean the contact in the column and at the end of the horn button?

 

the part the horn cap snaps onto

 

No clicking in the relay when you press the horn button.Had it working fine but it would not work the next morning.I will say again that the car was restored in 2003 and driven 1,800 miles in the next 21 years.