Author Topic: Horn honks when hooking up to battery  (Read 25681 times)

Offline MY1978

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Horn honks when hooking up to battery
« on: March 21, 2026, 06:49:10 am »
So, I apparently need high caliber brains to fix this.  I went to put the steering wheel back on, after trying to clock it, and I noticed that the steering wheel was on upside down, but because the wheels were turned slightly out.  So I started the truck, straightened them all without incident except then the horn would not blow.  So I pulled the steering wheel off, removed the locking plate and made sure the cancelling cam was seated correctly.  Put everything back together and when I went to hook the battery back up, the horn blew.  So AGAIN broke it down to the cancelling cam, AGAIN the horn blew.  So I decided to try just putting the cancelling cam and locking plate back in place - and the horn blows.  WTH!!!  it wasn't doing that when I started it to straighten the wheels.  Any thoughts or ideas.  Prior to this the horn was fine.  I was watching some videos and I will check the horn spring and fuse today.  I also have all the parts ready to order in my cart from where I have ordered parts from.

1978 Chevrolet, C10, 350,
« Last Edit: March 21, 2026, 07:01:33 am by MY1978 »

Online bd

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Re: Horn honks when hooking up to battery
« Reply #1 on: March 21, 2026, 08:30:39 am »
Either the horn relay control circuit is grounded, or the relay is faulty.  Does the horn blow with the lock plate and the cancelling cam removed?
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MY1978

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Re: Horn honks when hooking up to battery
« Reply #2 on: March 21, 2026, 09:21:27 am »
Was late yesterday when I threw my hands up and said I am done.  I am going to try that today.  I have some other things to do around the yard, then will go back to that.

Thanks

Online bd

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Re: Horn honks when hooking up to battery
« Reply #3 on: March 21, 2026, 10:19:36 am »
The resolution should be simple, and may be obvious once you direct your attention toward it in this new day.  Once you remove the c-cam, pay particular attention to the copper brush that rides up against the cam.  With the battery connected, depress the brush a few times using your finger to see what happens.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline MY1978

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Re: Horn honks when hooking up to battery
« Reply #4 on: May 03, 2026, 05:26:22 am »
Okay, it has been a few weeks since you replied and I do appreciate that.  Stuff just got busier, but back at it. 

I have not tried your suggestion yet about depressing what you call the "Brush".  I assume you are speaking of the button that makes contact with the c-cam.  I will try that.

But, I did notice that the locking plate is bent.  How you ask?  Because the tool to compress the plate was a wide one and the legs rested on the outer edge of the plate and bent the plate.  Probably the off, on, off, on, off, on caused it to get bent.  So I found, and ordered a replacement locking plate - came with new plastic cover and clip.  I also ordered a compression place/steering wheel puller kit, from our friends at Amazon, with a narrower compression plate tool.  I thought HA!!!!  problem is going to be solved.  I put the locking plate on, placed the clip in position, released the plate,hooked up the horn and BLAHHHHHHHHHH.   Well, dang!!!!! Disconnected the battery AGAIN. 

After I try your suggestion, if it doesn't work, I am going to order/buy a new canceling cam in case that somehow is now the problem.  Also ordering a new horn relay just in case although it was tested and seems okay.

This is getting REALLY frustrating.

Offline VileZambonie

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Re: Horn honks when hooking up to battery
« Reply #5 on: May 03, 2026, 07:20:15 am »
The canceling cam has the contact ring and they wear out. It's very common to have the horn randomly sound as you rotate the wheel when they're bad. Almost any auto parts store stocks them.

Dorman 83230 & 83232 for tilt column.

The contact is trim to length if you even need it.
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Offline MY1978

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Re: Horn honks when hooking up to battery
« Reply #6 on: May 03, 2026, 10:24:25 am »
Thanks.  This is a replacement c-cam because the original was broken a few years ago.  Before I took the steering wheel off to try and clock it since it was slightly off (which I wish I would have left the dang thing alone), it was working fine.  Like I said, I will get a new c-cam and relay to cover all the bases.


Offline JohnnyPopper

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Re: Horn honks when hooking up to battery
« Reply #7 on: May 03, 2026, 01:57:01 pm »
Looking to the outcome. I disco'd my horn a couple years ago due to random honkiness. Sure do miss it when certain Valedictorians are on the road... >:(
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline MY1978

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Re: Horn honks when hooking up to battery
« Reply #8 on: May 04, 2026, 07:53:06 am »
Looking to the outcome. I disco'd my horn a couple years ago due to random honkiness. Sure do miss it when certain Valedictorians are on the road... >:(

;D

Offline MY1978

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Re: Horn honks when hooking up to battery
« Reply #9 on: May 04, 2026, 07:55:47 am »
With the battery connected, depress the brush a few times using your finger to see what happens.

Sooooooo, we are hoping the horn does, or does not, honk.  Or will I honk because I will be shocked.   :-\

Online bd

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Re: Horn honks when hooking up to battery
« Reply #10 on: May 04, 2026, 11:39:52 am »
The brush rides against the cancelling cam brass ring.  The idea was whether the brush broke loose from the switch so that the back side (the wire terminal side) is grounding.  Try this: With everything above the turn signal switch removed, connect the battery.  If the horn honks the problem is physically limited to somewhere between the turn signal switch and the horn relay (e.g., the turn signal switch black horn wire is chafed to ground somewhere inside the column, the relay is faulty, etc).  If the horn does not honk, with the battery still connected, assemble the upper column one-piece-at-a-time to determine when the symptom appears.  Get the idea?  The cause of the problem is simple, but easy to overlook, especially if assumptions are made. 
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)