![]() |
|
![]() |
#1 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Horn relay
Where is it physically located on a '72 blazer? On mine, there's a black wire that runs from the horn into the fire wall. I was expecting the relay to be located in the engine compartment, but apparently not.
Thanks! |
![]() |
![]() |
![]() |
#2 |
Senior Member
![]() Join Date: May 2002
Location: Hammond, WI
Posts: 1,804
|
Re: Horn relay
i've got a pickup, but should be in the same spot. right above the fuse block inside the cab. rectangular piece, has 3 wires going to it.
__________________
Mike 2001 Dakota R/T - Silver CC - 1 of 1671 •360 w/46RE •392 limited slip 1972 Chevy Suburban - Turquoise/Black 1969 Chevy C/10 - Blue LWB •350 w/ 700R4 •3.73 posi •PS PB A/C - SOLD ![]() Using your turn signal is not "giving information to the enemy" 67-72 FAQ |
![]() |
![]() |
![]() |
#3 |
Registered User
Join Date: Jan 2012
Location: Kamloops B.C.
Posts: 5
|
Re: Horn relay
Mine is against the inner firewall between the top of the fuse block and the steering column three wire plug light gauge black and heavy gauge red & green. If your horn works unplug it and press the button you should hear the click of the relay.
__________________
1969 K5 400/400/205 |
![]() |
![]() |
![]() |
#4 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
The horn works when I apply a 12 volt source directly to it. The truck came with a funky steering wheel, which I removed, but the horn contact pieces were missing. I've bought some new parts from LMC, but still haven't got it working. Thought the relay might be bad, so now that I know where to look, I'll check it.
Thanks! |
![]() |
![]() |
![]() |
#5 |
Registered User
Join Date: Jan 2007
Location: Mississippi
Posts: 2,121
|
Re: Horn relay
The horn works from the steering wheel button by grounding. Be sure all the little pieces are clocked right & lined up correctly when pressed. Be sure all the contacts are good & clean too, a little scuffing with sandpaper usually helps.
__________________
'72 C to K20 "Cannibalizer" http://67-72chevytrucks.com/vboard/s...32#post8653432 '85 K30 "Big Nassy" '01 2500 Suburban ...party wagon & tow truck '06 Silverado SS...DD '06 C1500 WT...DD '07 Classic C1500 WT...DD Built & sold cause can't keep 'em all: '72 Blazer "The Bucket" http://67-72chevytrucks.com/vboard/s...d.php?t=433190 '55 Chevy straight axle gasser https://www.trifive.com/forums/showthread.php?t=173938 '69 Pro Street Chevelle http://www.chevelles.com/forums/showthread.php?t=332541 '86 M1031 CUCV http://67-72chevytrucks.com/vboard/s...d.php?t=553619 |
![]() |
![]() |
![]() |
#6 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
Still having some horn problems. Now I know why the P.O. must've disconnected the horn.
So to recap: with 12 volts applied directly to the horn it works. Replaced all the column horn components, grounded the steering wheel button and no horn. So then replaced the horn relay, grounded the horn button and got some buzzing and some smoke. Checked the horn relay and it had a hole in the side of it. So I know there's a short in the circuit somewhere, but I'm not sure where to start. I have one horn with a non-original wire running to the terminal The factory wiring diagram seems to indicate that a wire should go from the horn to the fuse panel. Is that correct? |
![]() |
![]() |
![]() |
#7 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
Bump. Anybody?
|
![]() |
![]() |
![]() |
#8 |
Registered User
![]() Join Date: Dec 2002
Location: Northern Virginia
Posts: 1,269
|
Re: Horn relay
I went over a speed bump and my horn went off. Pulled the plug and the horn stopped. But the battery went down. I was told the wire had shorted going down the column. Haven't check it out yet.
|
![]() |
![]() |
![]() |
#9 |
Registered User
Join Date: Jun 2009
Location: Hampton Roads VA
Posts: 333
|
Re: Horn relay
Get a multimeter and put it on ohms. Pull the connections one ant a time from the relay and put one lead on the wire and one to ground. If the needle moves that wire is shorted to ground. Follow that wire to find where it is rotted or worn through, you will probably have to replace it. OH and one of the connections should be a ground so that one is not a short lol. also the one to the horn should ground when you hit the horn button. Hope this helps a little.
__________________
Brad 72 Blazer CST 350/350/205 ![]() ![]() |
![]() |
![]() |
![]() |
#10 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
Still having horn problems. I've replaced the relay, signal switch, and cancelling cam. When I put the cancelling cam onto the steering shaft and push it down, the bottom brass part of the cancelling cam contacts the edge of the turn signal stalk, grounding out, and the horn goes off.
I'm not clear on how the horn components inside the steering column are supposed to work, so maybe I'm missing a part? But I don't think so, because I've compared the parts diagram in the LMC catalog and the repair manual, and it looks like I've got everything. I understand that when the barrell shaped copper button is pushed down and grounded the relay/horn is activated. And I'm assuming that the bottom of the cancelling cam shouldn't be contacting anything other than the copper button. There's very little clearance between the brass bottom part of the cancelling cam and the edge of the turn signal stalk - maybe there's a spacer or spring I'm missing? It's a non-tilt column, BTW. Could I get an explanation of how the horn parts inside the steering column work? Thanks! |
![]() |
![]() |
![]() |
#11 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
Man, this horn problem is really bugging me. So without the cancelling cam installed, I installed the steering wheel and the horn starts blaring. In order for the horn relay to be actuated, I thought the copper button must be depressed and the circuit completed by the steering wheel grounding to the steering shaft or something other metallic piece.
So I removed the new turn signal switch from the column to check for any wires that might have been damaged and possibly shorting out, but all looked good. With switch removed from the column, the meter shows 12 v between the copper button and the steering shaft. With the button pushed down, also get 12 v. I think it should be 12 v only with the button pushed down, correct? Perhaps the switch is bad? Any other possibilities? Thanks! |
![]() |
![]() |
![]() |
#12 |
Registered User
![]() Join Date: Dec 2002
Location: Northern Virginia
Posts: 1,269
|
Re: Horn relay
AS i stated earlier all the horn button guts are out of my steering wheel and horn is disconnected. I dont drive this blazer it needs floor pans in it. When I hook up the battery the relay under the hood clicks. If i hooked up the horn it will blow. I was told that the wire is shorted down the column. I have a 70 blazer that I bought. It has a push button installed for horn and is wired completely seperate. I havent looked to see if the horn wire coming down the column has been cut. I have seen several blazer with push button horn buttoms so this is a common problem I guess. I was almost thinking of getting a new painless wiring harness and changing it all when I get one road worthy
|
![]() |
![]() |
![]() |
#13 |
Senior Member
![]() Join Date: Jun 2000
Location: alb, nm
Posts: 413
|
Re: Horn relay
Yeah, that might be the easiest solution, but I'm really perplexed by this issue. The new turn signal switch comes complete with new wiring. It connects to a plug outside of the column so I don't think it could be shorting out inside the column, but ???
|
![]() |
![]() |
![]() |
Bookmarks |
|
|