The Stovebolt Site Forums The Shop Area The Electrical Bay Horn Replacement, 1 wire to 2 wire

OK. I give. I can't find a 1 terminal horn for my 56. How do you hook up a newer horn that has 2 terminals to the 1 wire I have going to the horn? Is one just a ground wire or is the horn grounded to the body where it is bolted down to? Thanks.

When I bought my truck it had a different horn button (2 wire) in it but no horn. I finally figured it out by trial and error :confused:

Lets see if this works.

From the horn button there are two wires.

One is grounded in the cab.

The other goes through the fire wall and is
spliced w/ the black wire that runs from the
horn relay to the engine harness (the one
where the lights hook up, that eventually
hooks to the fuse box). That group
of wires runs to one of the terminals on
the horn.

The other green wire from the relay goes to the horn.

Oh, I guess that depends if the 56 is the same. :o

Sorry if I might have made you more confused

Air horns are cool. They wake up the guy in the F**d in front of you. Just a thought.

A lot of new cars are plastic junk that dont conduct electricity, so grounding the horns to the body doesnt work,they need a seperarte ground. You may have one of those, or a dusl note horn.
I suggest you get a dvom (multimeter) and check for continuity between the 2 terminals, and between each terminal and the horns body. If there is continuity bettween the wires and the horn body, you have a dual horn. If the terminals are not grounded to the horn body, then one wire is ground.

OK. Let's see if I have this right.

1. Bolt new 2 terminal horn to radiator support (that's where the old one was).
2. Connect my single horn wire to one of the 2 terminals on the new horn.
3. Run a wire from the other terminal of the new horn to somwhere on the body to ground it.

How's that?

ordinarily the horn hooks to a relay which supplies power to the 1 terminal when the horn button puts a ground on the relay to activate it, and ground for the horn is the bolts that hold it. bolt the horn on and use any piece of wire [like a jumper cable] to quickly jump from the battery to either terminal of the horn to see what happens.

the way you've said it you may end up putting a dead short on yer battery the first time ya hit the button!

Bill

I think I see. So if I bolt the new horn to the body and it blows when I jump from the battery to either of the horn's terminal, I don't need to run a ground wire from the other terminal. I just hook my 1 wire to one of the terminals on the new horn and it should blow when I hit the horn button. Does that sound right?

Hey Old Blue;
That's exactly right. You run a hot wire (either from your battery or through the accessory side of your ignition switch) right to the + tab on the horn. Then you run the wire from your steering column to the - tab on the horn. When you push the horn button (which is, in essence, a switch), that completes the circuit to ground at your steering column. I assume that you have a 12v system which allows you to bypass the old horn relay. I did this with dual plastic Flamm horns on my 12v '49 GMC and it works like a champ.

Well yes and no. It is a 56 with the original 12 volt system, and it still has the horn relay. There was only one wire going to my original horn before it quit working. I just didn't know if a modern horn with 2 terminals would work with only the 1 wire my old horn worked with.

Oldblue , some of the new horn replacements are ment to work in the jap cars or german car whict are not wired the same as the older american (they use two wires) cars. The wire you took off your old horn put on one terminal (does not matter which) then make up a short wire to go from the other terminal to a good steel (not plastic) ground.

Wait a second, 49 geezer...don't you need to use a relay in that curcuit? Otherwise aren't you limiting the power to the horn by the gauge and impedence of the wire running all the way from the battery to the horn button on the steering wheel and then back to the horn? Not to mention the heat if you really lay on the horn for a minute or the button sticks.

When I did this without the relay, I got a weak wimpy horn tone.

I ran my wire from the horn switch to the relay and ran power from the battery direct to the relay. Horn switch/button gets it's ground from the column, relay gets it's ground from the radiator support, power comes to the relay and through to the horn when the relay closes. Horn gets it's ground from the mounting point or a ground wire bonded to the radiator support.

Same's true with switching to halogen headlight bulbs...a relay is the right way.

Just my two-cents worth...I could have mis-understood the instructions above.

Hey C!
Don't know if what you said is a problem or not. Just know that it wasn't a problem on mine. No horn relay. Bought two (one hi, one lo) horns from Trak Auto. Mounted them on the firewall behind the grille. Ran a 12v hot from the headlight switch to the + of both horns and from the - back to the steering column wire. Horns work great, button doesn't stick and I get attention when I need to. Anyway, works for me! :p

If it ain't broke.....keep fixin' on it.