i have replaced horn relay, turns out needed to replace horn bar and steering wheel, horn still does not work nor hazards, tested horn with wire to connection and it works. am looking at plastic/nylon unit inside steering column and am wondering if it is bad. any thoughts?

 

I don’t claim to be a wiring guru by any stretch, but my first guess would be no power in the steering column. You should have 12v at the horn ring under the steering wheel that blows the horn when activated. Could be the same going to the hazard switch.
Could be a ground problem in column too

 

Thanks, that was something i never considered, it was very helpful

 

The flex joint where the steer column meets steer box, known as the wrag joint, is insulated, there is a flex copper strip in there you can't see. When the strip breaks the steering column loses it ground(ing) capabilities. The horn wont blow. You can test with a booster cable. Use each end of red or black, 1 cable, attach 1 to the side of joint at box and other end to the steer column flange. Try your horn. There are numerous links thru the wheel to in column signal light switch, that can be broken and again, no horn blow. Cap.

 

wow, i hope thats not it, i discovered horn bar requires 2 contacts, my unit only had one, i got another signal/horn/hazard unit and removed the contact and inserted in my unit, now am working on where to insert the wire into the connector

 

i discovered horn bar requires 2 contacts, my unit only had one, i got another signal/horn/hazard unit and removed the contact and inserted in my unit, now am working on where to insert the wire into the connector

 

Yes on the 2 contractors under the steer wheel. One in sig switch other thru the wheel. Both spring loaded. To help cut the chase. There are 3 wires on the horn Relay. 1 to horn, other to battery side of starter solenoid. The 3rd wire is hot/live and goes thru the wiring harness of the truck to the signal light switch spring loaded connector. IF you have a test light you can test the spring connector for power, the light should lite. If so, you ground connector any where except the steer column and the horn should blow. As far as the strip in the wrag joint being broken, make jumper wire connecting, with a comfortable loop, the bolt on the column shaft to the bolt on the coupling on the steering box, you now are restoring the ground of the column to the rest of the truck.

 

I am sensing a parts miss-match, on a '74 steering wheel, there should only be one ring, and one brass contact from the switch, unless you have cruise. A '78 wheel has two of each. The horn is independent of the turn signal circuit, anything there is a separate issue.

 

Agreed, the horn is separate from the signal light circuit but, the horn circuit is carried thru the Nylon signal light switch assembly. I'm sorry I can't send pictures at this time as I'm away doing these postings on my phone. I do admit there may be a difference I'm not aware of in the 74/79 sig switch/horn assembly than the 61/66 - 67/73 columns I'm most familiar with. Cap

 

I'm going mostly on memory, as my trucks are 30 miles away, but the OPs 74 should be similar to a bumpside switch, but with an added 4 way flasher. '78, however is a very different column, and wiring. If everything on the OPs truck is '77 or earlier, the parts should be compatible. Cruise control was available in dentsides, so some early steering wheels have 2 rings for that reason, but only one is used for the horn.
tamgc, I may have misread your thread, but are you putting a 2 pin TS switch in? If the TS switch has 2 brass contact pins, it is either for cruise, or it is the wrong year, I have seen lots of early trucks, with later columns retrofitted.

 

thanks for all the info, every bit helps. yes found that 74 with horn bar had only one contact so will not be putting in another, turns out the signal harness is "new" within a couple of years. right now have discovered no power at relay connector and am trying to resolve that. the engine is rebuilt '71 302 with 2 barrel carb and electronic ignition, it has a new solenoid and am wondering if it is correct for engine but not for 74 wiring. the left pole of solenoid is connected to starter and horn relay connector, then there is a number of connectors in the area that i am trying to identify their use.
the yellow wire from horn relay to ring terminal on solenoid has connectivity but shows no current unless you turn on ignition and then it shows negative 2.6 volts. crazy and driving me there as well

 

One thing I read as wrong or you said wrong. Correctly the wire that feeds the Horn Relay, attaches to the positive battery cable side of the starter solenoid. The other side of the solenoid only has the cable to the starter. As we try to help, if you can post a picture of what we're speaking of, we might get a greater grasp of things wrong.

 

We'll hang with you to resolve. Don't get disgusted, remember, We Can't See what you have there. When I get back I will try to post some pic's of all being talked about.

 

i'll take some pics as well