The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-30-2013, 11:03 PM   #1
Lattimer
Registered User
 
Lattimer's Avatar
 
Join Date: Jan 2013
Location: Mickleton, NJ
Posts: 1,776
Horn issues

So, my horn didn't work when I got the truck a month ago. As I have been working through various issues, I've been replacing a lot of parts and fixing all sorts of PO screw ups.

Horn itself was no good, so I replaced with a basic Wolo low tone. Wiring in the engine compartment was half melted and bare in spots so I replaced it back to the firewall. Found the plug at the relay disconnected and melted, so I installed a new relay and spliced in a new plug.

I have also replaced the steering column with a new tilt column and replaced the steering wheel with a new Grant wheel, new horn button, etc., so everything except the under dash harness is essentially new.

If I short across the plug at the relay, I can get the horn to honk. And that is the only way. Shorting the horn button inside the column does nothing, so I think my issue is between the column and the horn somewhere. I'm about to splice into the wires at the column and just run all new to the horn from there and abandon the factory wiring, as I am pretty much out of ideas.

Anybody have any insight as to what else I can look for? Anything hidden under the dash I'm not aware of?
__________________
Shawn

1970 Chevy C-10 SWB, 350, TKO 600 5 speed
My build http://67-72chevytrucks.com/vboard/s...d.php?t=559881
Lattimer is offline   Reply With Quote
Old 02-01-2013, 12:51 PM   #2
Lattimer
Registered User
 
Lattimer's Avatar
 
Join Date: Jan 2013
Location: Mickleton, NJ
Posts: 1,776
Re: Horn issues

Bump....Anybody got any ideas for me, or is it probably just a bad wire?
__________________
Shawn

1970 Chevy C-10 SWB, 350, TKO 600 5 speed
My build http://67-72chevytrucks.com/vboard/s...d.php?t=559881
Lattimer is offline   Reply With Quote
Old 02-01-2013, 01:58 PM   #3
Stocker
20' Daredevil (Ret)
 
Stocker's Avatar
 
Join Date: May 2003
Location: Jefferson State
Posts: 13,586
Re: Horn issues

I read this yesterday and thought there might be replies by now. All you should have to do is ground the wire at the horn button, and that will operate the relay. There may be a connector in the wire but I'm not aware of one. My guess is a bad wire (or possibly a bad connector) from the horn to the relay. This assumes that you are sourcing a good ground at the horn button.....

You've already proven everything good from the relay to the horn.
__________________
- Mike -

1972 K20 LWB 350/350/205

RIP El Jay
Stocker is offline   Reply With Quote
Old 02-01-2013, 02:27 PM   #4
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,709
Re: Horn issues

Your horn relay has three terminals that a large 12 gauge red and a 12 gauge green wire connect to in the plug. It also has a smaller black wire in the plug that grounds the coil ain the relay and electrically shorts the green and red wires to blow the horn. If you rewired the plug you might have gotten these wires in the wrong position in the plug. The black wire goes into the harness and up into the column through a crescent shaped connector for the brakes and turn signals and then to the horn button where it is grounded by the horn button and energizes the horn relay. At least that's how it's supposed to work.


The grant steering wheels have a reputation for not working the horn relay and the column may not be grounded as well as it should be. IF you can access the black wire for the horn button, try grounding it to the column and see if the horn blows.

Here's a picture of the relay and the plug and the crescent connector.
The black horn wire is at the top of the connector.
Attached Images
  
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 02-01-2013, 02:45 PM   #5
Ol Blue K20
Proprietor of Dale's Corner
 
Ol Blue K20's Avatar
 
Join Date: Nov 2012
Location: Vacaville , CA
Posts: 15,999
Re: Horn issues

I have had the steering shaft loose it's ground at the rubber coupler test for continuity from one side to the other. Sometimes if someone replaces it with a cheap universal fit they don't put the ground strap in it. The steering shaft grounds through the steering box
__________________
"Some Days Chickens And Some Days Feathers"

Dale
XNGH ECV Sam Brannan 1004

R.I.P. 67ChevyRedneck
R.I.P. Grumpy Old Man

Last edited by Ol Blue K20; 02-01-2013 at 03:05 PM. Reason: bad grammer
Ol Blue K20 is offline   Reply With Quote
Old 02-01-2013, 03:26 PM   #6
Lattimer
Registered User
 
Lattimer's Avatar
 
Join Date: Jan 2013
Location: Mickleton, NJ
Posts: 1,776
Re: Horn issues

Thanks! Now I have some more stuff to check.

I'm pretty sure I got the connector wires correct, but I will double check.
__________________
Shawn

1970 Chevy C-10 SWB, 350, TKO 600 5 speed
My build http://67-72chevytrucks.com/vboard/s...d.php?t=559881
Lattimer is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:29 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com