'67 horn won't work...

[Eagle Flight]

I need some help, I recently got a '67 coupe :s , everything works great except the horn. I've checked the grounds and replaced the horn brush/spring in the steering column, I see good current and contact in the steering column, so I suspected the horn relay. Checked the fuseable link that connects to the relay and it is still good.

Got a new relay from Corvette Central and it has an extra connection in the middle of the body that the old one didn't have. (old one had the green horn plug-in connection, a black small wire plug-in connection, and the 2 screw in side post wires, one with side crimped red wire and one marked 'batt' with a straight crimped red wire - the old relay also had the separate fuesable link wire tied in at the bolt on terminal with the side crimped red wire, so I put it the same way). :confused

Hooked it all up with the new relay and no joy. Since it did not work before, I have little confidence in the original config and do not know what to do with the extra connection point on the new relay either. I have the service manual wiring diagram but it doesn't help much either.

;help Anyone out there had horn problems or able to help? Without the horn I cannot pass a safety inspection in Texas, so can't really drive it around much... (potential $40 ticket :cry )

 

[Eagle Flight]

By the way, there was one more wire from the harness that was a ground type and was connected to the bolt that holds the horn relay to the radiator frame, I also put that the same way on the new horn relay (a borg warner replacement).

Thanks, Eagle Flight

 

[Mikey1]

Simple question....

...have you checked the horns themselves by pulling them out and connecting each one to a battery (has to be a one for a car)...

My horns where both gone !

 

[JohnZ]

Chances are the extra connection on the new one is for a later car with the key buzzer. The screw connections are for 12V power, the green wire feeds the horns 12V when the relay is closed, and the black wire goes through the fuse block and ends up at the horn button and grounds the relay coil to the chassis through the steering shaft, rag joint, and steering gear when you push the button.

Make sure the copper ground strap across the "rag" portion of the rag joint hasn't corroded or broken; use a jumper wire between the upper and lower steel flanges of the rag joint and see if the horn works - if it does, you've lost the ground through the rag joint. You can also check the relay (see if it "clicks") by disconnecting the black wire and using a jumper wire from that terminal to a convenient ground - if no click, the relay isn't working. All this assumes you've checked the horns themselves (and their grounds through the attaching bolts) with a jumper from the battery to make sure they actually work when you put 12 volts on them.

 

[Eagle Flight]

Ok, I took a horn I know works from my 67 Mustang and installed it into the vette circuit in place of one of the original horns (and grounded it). No joy. I did check and both horns are well grounded to the radiator frame (w/ground wires). I will try the tests on the relay that JohnZ suggested next.

Thanks for the positive thoughts so far, this is very frustrating!

JohnZ, so basically I would leave the key buzzer connection alone and just hook the new relay up like the old one? That makes sense because it did buzz when I tried a few configs with that connection attached.

BTW, very nice blue convertible.

 

[markiemyster]

Nice pics...

Eagle Flight,
Nice cars. You certainly have two classics.
Good luck, Mark

 

[Eagle Flight]

Thanks! I think some of the best cars were made in '67!

I've made some progress... I pulled the black connection on the horn relay and grounded there for a second, the horns played loud and clear for the first time! So clearly the problem is getting the ground signal down from the steering column (thank you JohnZ! :BOW )

Now about this rag joint, I placed various ground points along the steering column shaft in the engine compartment down to the steering coupling (I found no ground straps across any portions by the way :confused ) Did not seem to make any difference, but I am probably doing it wrong. I have the 67 assembly guide and the service manual but neither mention a ground strap. Any ideas? I feel like I must be close to solving this problem, having actulally HEARD the horns and all!

 

[JohnZ]

Depends on whether it's an original or replacement rag joint - some used a thin copper ground strap, some used a copper mesh embedded in the "carcass" material. If you jumper across the two flanges and still have no horns (now that you know the relay and the horns work), the problem is either in the bulkhead connector where the horn wire goes into the engine compartment side of the fuse block, or you have a bad horn contact assembly (the gizmo under the horn button that attaches with three screws).

Go into the curved harness connector under the dash on the steering column with all the directional wires in it; one end will have an empty cavity, with a 20-gauge black wire in the second cavity from the end. Stick a probe into that cavity and ground the other end, and the horn should blow - if not, you don't have continuity from there to the horn relay (which that wire grounds). If the horns blow, then you aren't getting a ground at the horn contact button end.

 

[Eagle Flight]

Update: For today, Tried the grounding at the curved harness connector, just as JohnZ recommended and grounded the second cavity in from the left (first one empty, second one black). No joy, only silence :nono . I then disconnected the harness at the engine compartment side of the firewall and verified good continuity on the horn ground circuit from the horn relay back to that point. It's good to there.

I think this tells me that the problem lies between the firewall connector and the curved harness. It looks like to get to inspect anything further I've got to pull the fuse box to see what's going on behind it where the wires go into the firewall mounted connector :bash . Is that straight forward if I just undo the bolt on the bottom left side of the fusebox behind the bottom fuse, or will I be causing more problems? What awaits me there? Am I on the right track?

Thanks for your help JohnZ !

 

[Vetsvette2002]

If you e-mail me with your real name and address, I can send you a full color wiring diagram for the 67. I drew it in AutoCAD 14 and is printed at 22"x34" in full color with fuses, lights and all options that require electrics for coupes or convt.s

my ady is

vetsvette2002@yahoo.com

Don

 

[JohnZ]

You can check continuity of that black wire from the connector terminal on the engine side of the fuse block to where that wire comes out of the top of the fuse block (and heads for the curved connector) without removing the fuse block from the firewall. In that bundle of wires coming out of the top of the block, there's only ONE 20-ga. black wire, and that's the horn ground wire; check continuity between the connector pin on the engine side and pierce-probing that black wire just above the fuse block and that will tell you if you have a good circuit through the innards of the fuse block. If you don't show continuity, then remove the fuse block and separate the two halves to locate the break. If continuity is OK, you know it's been lost in the harness between where you probed and the curved connector body.

 

[Eagle Flight]

:cool Great news! I traced it all down and now have a working horn! Life is good again!!

Thanks to all for your help in this effort. It's great to have a forum where technical items like this can be discussed. Much appreciated!

Eagle Flight

 

[JohnZ]

Glad you got her fixed - now you can blow the horn and get those ricers out of the way