A few years ago my 52 3/4 ton was converted from 6 to 12 volts (kept the 6 volt horn in). Trying to figure out why the horn no longer works, took the steering wheel off and I can't remember what's what in there. Should I be using a "Horn Spring Bushing" (aka "Horn Contact and Spring")? I also see something on line called "Horn Contact Brush 6 Volt Without Relay Fits in Steering Wheel Chevrolet" which looks different but I assume is only for a 6 volt system. Also, does it still need a "Horn Button Spring" (didn't see one in there)? I appreciate any help with this!
This is from a GMC of the same year and size. I assume it is the same.
In the GMC Master Parts Bok 7.6920 is called "horn button contact", 7.7000 is "horn button insulator" and 7.7150 is "horn button spring". If you replace the contact make sure there isn't paint on the surfaces where the top and bottom contacts meet. Got one like that from one of the old truck parts vendors on time. Looked good, didn't work.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
By the way, if the horn is still wired as originally designed (no relay, all horn current passes through the switch in the steering wheel) I'd seriously consider installing a relay. Easy to do.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
rockhammer Your horn parts are all part of a ground circuit that makes the horn work,the horn button is mounted on an oil can bottom type spring. Under thebutton mount (held by the steering nut) you will find that brush which rubs on the perimeter of the shaft bearing mount. A coil spring holds tension an that bearing,you can easily take the brush and insulator tube out to inspect for wear. Hope that helps.
If your horn has two terminals one will be battery + Positive (12v hot all the time) and the other is battery - (Negative) that passes through the horn switch. Remove both wires from the horn and figure out which is the 12v + (Positive) with a multi-meter. Reconnect the + (Positive) to the horn. Then use a jumper wire from the battery - (Negative) and touch the other terminal on the horn...did it sound? If not the horn needs attention, if it did then the horn switch wiring need attention.
If you only have one terminal on the horn then you have a relay in the circuit and it switches the battery + (Positive) ...use a jumper wire from the battery + (Positive) and touch the horn terminal and it should sound as long as the ground path is all clean.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD
