Am I correct that the steering column is insulated from the truck body at the under gauge area and down at the firewall? Thus the horn electrical connection only goes through the wires? I made a nice custom steering column mount that is secured to the firewall and I am thinking this is why I am having trouble making the horn work correctly. Haasman
If your 51 Chevy has stock horn wiring and if your Chevy wiring matches my 52 GMC ,horn wiring, there is an "always hot" 6 volt wire connected to one terminal on your horn. The other wire runs up into the steering column to the insulated ring at the top up the column. From there it passes through that contactor in the steering wheel to the bottom of the horn switch. When you mash the horn button it makes connection across the switch to ground through the steering shaft. The shaft should be grounded through the steering box. I didn't like all that current flowing through the horn switch, so I installed a relay. This mod also got rid of the "always hot" wire on the horn.
Bill- yes I do have the wires running up the steering column and to the horn button contact. The problem is this horn circuit is always on. I was thinking that since I have a metal-to-metal connection of the steering column to the truck firewall, that it was getting grounded out. Is the steering column supposed to be isolated from the metal of the truck body?
I do have a relay. The work on my truck is a total restoration so I am bring all the parts and pieces together. When I ran the wiring for the horn contact in the center of the steering wheel, I notice it was a constantly closed connection. As if the horn button assembly was working all the time. Thus my question about whether the steering column is supposed to be isolated from the truck with the big firewall gasket and under the gauges.
Pull the horn button, the nut under it, the horn switch under the nut and the contactor under the horn switch. Then see if the circuit is still "on". If it is not on, most likely culprit is the horn switch. If it is still on I'd guess that the relay is wired incorrectly.
I had the "horn on" all the time after I replaced the Steering Column Bearing. Problem was the very top of the bearing unit was touching the steering column. It was completing the circuit creating the "horn on" all the time. No metal part of the bearing can touch the steering column. After I backed out the bearing unit, just enough from touching the top of the column, problem solved.
Is your relay like this? If so, the horn(s) should connect to the left terminal, battery to the center terminal and the right terminal connects to the horn button via the upper mast bearing outside lip as Tom stated above, then through the contact/brush that looks like this. If anywhere along this path you touch ground, the horn will blow. If you have an ohmmeter you can easily find the point that is grounded.
I went back and read your earlier posts again Mr. Haasman. I have a question. What do you mean in the statement above? It is normal to read battery voltage on the outside lip of the mast bearing, the contact brush and the bottom surface of the horn switch. When you push the horn button, you ground this voltage and pull in the horn relay.
Sorry for the long delay in replying- what I mean is the connection across the horn contact at the top of the steering column.
When the horn button is NOT pushed, it should read battery voltage on the bottom of the horn switch contact to the top of the horn switch contact. It should also read battery voltage from the bottom of the horn contact to ground. When the button is pressed both top and bottom contact should read zero volts to ground. Given that you have a horn relay, you can unplug the wire(s) from the horn(s) and just listen for the relay to click when you press the horn button. Makes it nicer for the neighbors with the sleeping baby.
