Alarm Horn Removal
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,073
Likes: 331
From: Clear Lake Shores Texas
2016 C3 of Year Finalist
Alarm Horn Removal
I need to remove the alarm horn from my 72 to have it rebuilt. I have searched the archives but couldn't find a definitive answer to my question - does the drivers side muffler have to be removed to gain access to it or is there another way to unbolt it, such as through the right rear wheel well?
Thanks in advance for any advice.
Thanks in advance for any advice.
Advanced
Joined: Sep 2014
Posts: 52
Likes: 16
From: Savannah Georgia
I need to remove the alarm horn from my 72 to have it rebuilt. I have searched the archives but couldn't find a definitive answer to my question - does the drivers side muffler have to be removed to gain access to it or is there another way to unbolt it, such as through the right rear wheel well?
Thanks in advance for any advice.
Thanks in advance for any advice.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
Hi Dan,
Yes, it's a lot easier if you can move the muffler over a little. Just remove your tip from the muffler if you can. That should help. I would also suggest spraying some LPS or PB blaster on the bolt if it has never been removed. Just be careful the spray doesn't get in your eyes when your lying under the car spraying up. Also use caution pulling the wire off the horn as to not break the connector if heavily rusted.
Just a suggestion before sending out your horn. Spray some LPS on the small adjusting screw on the back of the horn. Let it soak awhile. Then carefully try to turn the adjuster, use small vice grips. Once loose, turn it all the way in then out, not completely out though. Get two wires and connect to a twelve volt supply. Negative to the horn mounting bracket after it is cleaned of all rust, and the positive to the horn wire connector after you've cleaned it. See if the horn tries to blow. If you get a thud sound try adjusting the screw in various positions to see if you get it to sound. If you get nothing then it will need taken apart. To check continuity and clean the contact pts.
I've included some pictures below to show the different horn parts. It's not easy, but it is a fun project to work on and restore the horn.
Regards,
Jimmy
Yes, it's a lot easier if you can move the muffler over a little. Just remove your tip from the muffler if you can. That should help. I would also suggest spraying some LPS or PB blaster on the bolt if it has never been removed. Just be careful the spray doesn't get in your eyes when your lying under the car spraying up. Also use caution pulling the wire off the horn as to not break the connector if heavily rusted.
Just a suggestion before sending out your horn. Spray some LPS on the small adjusting screw on the back of the horn. Let it soak awhile. Then carefully try to turn the adjuster, use small vice grips. Once loose, turn it all the way in then out, not completely out though. Get two wires and connect to a twelve volt supply. Negative to the horn mounting bracket after it is cleaned of all rust, and the positive to the horn wire connector after you've cleaned it. See if the horn tries to blow. If you get a thud sound try adjusting the screw in various positions to see if you get it to sound. If you get nothing then it will need taken apart. To check continuity and clean the contact pts.
I've included some pictures below to show the different horn parts. It's not easy, but it is a fun project to work on and restore the horn.
Regards,
Jimmy
Last edited by Tooch1; Sep 28, 2016 at 09:42 AM.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
Restored horn, that only needed the adjusting screw pictured above loosened and then adjusted to get the proper horn note. This one was media blasted and then repainted. Which I did not do. The guy could not get the horn to sound, so I bought it cheap and luckily got it working with the screw. I keep it as a spare. My original on the car , I did need to take apart and fix.
Regards,
Jimmy
Regards,
Jimmy
Last edited by Tooch1; Sep 28, 2016 at 11:13 AM.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
Horn wire connector. Be careful not to break this off when trying to remove your wire. Especially if it has never been removed in over 40+ years.
Last edited by Tooch1; Sep 28, 2016 at 10:12 AM.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
What the horn parts look like disassembled. The horn is just like an electro magnet. It has a coil of wire connected to a set of points. The electric charge travels through the wires and causes points to react which cause the center plate to vibrate making the horn sound. If the wire coil is not broken anywhere and you have continuity you can more than likely if your lucky get the horn to work by cleaning the points contacts. All the rust needs cleaned from all parts, and you'll also need to remake the gasket that goes between the two parts of the horn.
The original rivets holding the horns together are not designed to be removed, they need ground off on the bottom and punched back through.
A lot involved in this, and probably more than you ever wanted to know. That's why most guys send them away. But I enjoyed the challenge.
Keep in mind that the alarm horns are not dated. They only have a 3,digit number like the one above 939. Some might have 936? So, that being said, what you may be paying to have it restored may be more than finding one that works on line. Even if you are having the car judged, the best a judge can see is if the horn is there, it's overall condition and if the original rivets have been removed and replaced by something different. Just a thought.
The original rivets holding the horns together are not designed to be removed, they need ground off on the bottom and punched back through.
A lot involved in this, and probably more than you ever wanted to know. That's why most guys send them away. But I enjoyed the challenge.
Keep in mind that the alarm horns are not dated. They only have a 3,digit number like the one above 939. Some might have 936? So, that being said, what you may be paying to have it restored may be more than finding one that works on line. Even if you are having the car judged, the best a judge can see is if the horn is there, it's overall condition and if the original rivets have been removed and replaced by something different. Just a thought.
Last edited by Tooch1; Sep 28, 2016 at 10:09 AM.
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Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 1,073
Likes: 331
From: Clear Lake Shores Texas
2016 C3 of Year Finalist
Thank you very much for the detailed pictures and explanations, they will help a lot. It definitely motivates me to get to work on it.
Team Owner
Joined: Sep 2006
Posts: 31,301
Likes: 4,389
From: Westminster Maryland
Hi Jimmy,
Nice pictures on the horn!!
Is one side (with the trumpet) plastic and the side with the bracket steel? The rust situations makes it appear that way.
Regards,
Alan
Nice pictures on the horn!!
Is one side (with the trumpet) plastic and the side with the bracket steel? The rust situations makes it appear that way.
Regards,
Alan
Last edited by Alan 71; Sep 29, 2016 at 08:25 AM.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
Sorry I took so long to respond. My wife and I just got back late yesterday from an 8 day Pacific NW cruise. The top section of the horns are pot metal not plastic. In the photos above of the three parts the bottom is the underside of the top section of the horn.
Regards,
Jimmy
Last edited by Tooch1; Oct 10, 2016 at 09:58 AM.
Racer
Joined: Mar 2007
Posts: 250
Likes: 11
From: Turnersville, NJ
Great information!! ... I'm working on my 72 alarm too. Have it working now but when it's engaged the horn is just making a flashing clicking noise. No horn. I'm going to take the horn out and try your advice. Curious, what size wrench is needed on the one bolt to take it off? If I can't get it to work I'll look to buy one if I can find one on this site. Or, someone to fix it.
Burning Brakes
Joined: Oct 2013
Posts: 1,115
Likes: 520
From: McClellandtown, Pa.
Great information!! ... I'm working on my 72 alarm too. Have it working now but when it's engaged the horn is just making a flashing clicking noise. No horn. I'm going to take the horn out and try your advice. Curious, what size wrench is needed on the one bolt to take it off? If I can't get it to work I'll look to buy one if I can find one on this site. Or, someone to fix it.
Great to hear you are going to work on the horn yourself. I'm not positive it's been awhile but the bolt should either be a 1/2 or 9/16 inch. As I stated above, before you take it apart loosen the adjusting screw and try turning it one way or another to see if the horn starts sounding. If you do grind off and remove the rivets here are the 'Socket Head' screws I bought in Lowes. I used the size pictured, but I've been told that 8x32 size head is a bit smaller and looks more like the original rivet once you fill in the hole in the head and paint it satin black. These work perfectly to put the horn back together because the original rivets are no longer usable. Let me know how things work out.
BTW- if you don't get it to work find a working used one on this site, or they are always on eBay.
Tooch
Last edited by Tooch1; Jan 28, 2017 at 06:59 PM.
Race Director
Joined: Oct 2008
Posts: 19,258
Likes: 1,678
From: Long Island
great pictures, thanks. I just rebuilt mine also.
I used Allen screws and ground the ribs off the outside of the bolts. Filled the Allen with JB weld.
I also rebuilt the switch - the back was missing - electrical part.
I made the rear plate out of nylon. ( what is white when you see them in the pictures)
I used brass rivets (ace hardware) to hold the "arms" on the back nylon. They also acted as the contacts.
I used hobby store brass to make the part of the switch that turns inside the key switch.
I used the spring from a small mag light to push the part that turns against the rivets.
Then JB welded it together as I was afraid that the nylon wouldn't stay in the switch and I was afraid it would pop out as the original did. I did not want to squeeze the metal.
It works- I only made one mistake - I used brass to make the electrical arms of the switch (where the wires attach) - they should be metal.. I'll paint them I guess.
I should have taken pictures.. didn't think anyone would be re-building the alarm..
I used Allen screws and ground the ribs off the outside of the bolts. Filled the Allen with JB weld.
I also rebuilt the switch - the back was missing - electrical part.
I made the rear plate out of nylon. ( what is white when you see them in the pictures)
I used brass rivets (ace hardware) to hold the "arms" on the back nylon. They also acted as the contacts.
I used hobby store brass to make the part of the switch that turns inside the key switch.
I used the spring from a small mag light to push the part that turns against the rivets.
Then JB welded it together as I was afraid that the nylon wouldn't stay in the switch and I was afraid it would pop out as the original did. I did not want to squeeze the metal.
It works- I only made one mistake - I used brass to make the electrical arms of the switch (where the wires attach) - they should be metal.. I'll paint them I guess.
I should have taken pictures.. didn't think anyone would be re-building the alarm..
Last edited by BLUE1972; Jan 28, 2017 at 09:39 PM.
Racer
Joined: Mar 2007
Posts: 250
Likes: 11
From: Turnersville, NJ
great pictures, thanks. I just rebuilt mine also.
I used Allen screws and ground the ribs off the outside of the bolts. Filled the Allen with JB weld.
I also rebuilt the switch - the back was missing - electrical part.
I made the rear plate out of nylon. ( what is white when you see them in the pictures)
I used brass rivets (ace hardware) to hold the "arms" on the back nylon. They also acted as the contacts.
I used hobby store brass to make the part of the switch that turns inside the key switch.
I used the spring from a small mag light to push the part that turns against the rivets.
Then JB welded it together as I was afraid that the nylon wouldn't stay in the switch and I was afraid it would pop out as the original did. I did not want to squeeze the metal.
It works- I only made one mistake - I used brass to make the electrical arms of the switch (where the wires attach) - they should be metal.. I'll paint them I guess.
I should have taken pictures.. didn't think anyone would be re-building the alarm..
I used Allen screws and ground the ribs off the outside of the bolts. Filled the Allen with JB weld.
I also rebuilt the switch - the back was missing - electrical part.
I made the rear plate out of nylon. ( what is white when you see them in the pictures)
I used brass rivets (ace hardware) to hold the "arms" on the back nylon. They also acted as the contacts.
I used hobby store brass to make the part of the switch that turns inside the key switch.
I used the spring from a small mag light to push the part that turns against the rivets.
Then JB welded it together as I was afraid that the nylon wouldn't stay in the switch and I was afraid it would pop out as the original did. I did not want to squeeze the metal.
It works- I only made one mistake - I used brass to make the electrical arms of the switch (where the wires attach) - they should be metal.. I'll paint them I guess.
I should have taken pictures.. didn't think anyone would be re-building the alarm..
Racer
Joined: Mar 2007
Posts: 250
Likes: 11
From: Turnersville, NJ
Hi,
Great to hear you are going to work on the horn yourself. I'm not positive it's been awhile but the bolt should either be a 1/2 or 9/16 inch. As I stated above, before you take it apart loosen the adjusting screw and try turning it one way or another to see if the horn starts sounding. If you do grind off and remove the rivets here are the 'Socket Head' screws I bought in Lowes. I used the size pictured, but I've been told that 8x32 size head is a bit smaller and looks more like the original rivet once you fill in the hole in the head and paint it satin black. These work perfectly to put the horn back together because the original rivets are no longer usable. Let me know how things work out.
BTW- if you don't get it to work find a working used one on this site, or they are always on eBay.
Tooch
Great to hear you are going to work on the horn yourself. I'm not positive it's been awhile but the bolt should either be a 1/2 or 9/16 inch. As I stated above, before you take it apart loosen the adjusting screw and try turning it one way or another to see if the horn starts sounding. If you do grind off and remove the rivets here are the 'Socket Head' screws I bought in Lowes. I used the size pictured, but I've been told that 8x32 size head is a bit smaller and looks more like the original rivet once you fill in the hole in the head and paint it satin black. These work perfectly to put the horn back together because the original rivets are no longer usable. Let me know how things work out.
BTW- if you don't get it to work find a working used one on this site, or they are always on eBay.
Tooch
Instructor
Joined: Nov 2013
Posts: 128
Likes: 29
From: Bloomfield Township Michigan
Jeff
Racer
Joined: Mar 2007
Posts: 250
Likes: 11
From: Turnersville, NJ
I recently removed the alarm horn from my '69 and used a good Kroil penetrating oil and sprayed it from the wheel well side so I was spraying the threads that protruded through the mounting plate. I have gotten 3 different horns that appeared dead to work perfectly. Unless the coil wire is broken or the corrosion has destroyed the metal inside, there is no reason that you can't get any horn to work.
Jeff
Jeff
Instructor
Joined: Nov 2013
Posts: 128
Likes: 29
From: Bloomfield Township Michigan
Jeff
Racer
Joined: Mar 2007
Posts: 250
Likes: 11
From: Turnersville, NJ
Used Alarm Purchase or Rebuild
If you are going to use WD40 and that bolt is really in there, I think you will be disappointed. In my opinion, you need a high quality penetrating oil. I have found that Kroil is the best commercially available one out there. Some have suggested that a 50/50 mix of ATF and lacquer thinner works well but I have not tried it. Keep is posted.
Jeff
Jeff
After getting it off, I was able to turn the adjustment **** as Jimmy suggested and seemed to find the soft spot that I needed. Unfortunately, I may have let the alarm sound too long and get too hot as now I can't get it to work at all, no matter what I try. I may have burnt it out.
At this point and after seeing the work ahead to get the alarm apart and working again ... I think it may be wise for me to either have this one rebuilt by someone knowledgeable at this, or buy a used working alarm. Anyone know anybody who has one for sale? ... or, a reliable individual to rebuild mine? Let me know, please. Thanks!