My first Jeep was my uncle's 1948 CJ-2A that he kept at my parent's house. He lived out of state and it was there for mostly hunting season or when he came to visit, which was basically only fall hunting season. When I got my license, my dad got tired of me borrowing his or my mom's car all the time, so he asked his brother if I could drive "Big Red". Luckily, I'd helped my uncle working on it all the times it needed something done, so I was rewarded with having it be my ride all through high school. No seat belts, no power anything, but it had appeal like nothing else. It's still there, dad starts it every now and then to keep things moving, but it's no longer a daily driver.
When I got my 2005 LJ, I didn't plan on making many modifications. For some reason, in the last month I just had this urge to make my current Jeep a little like that old Willy's. Aside from its Go Devil engine, then most "Jeep" thing about that old Jeep was its horn. So I got searching, initially for a Sparton horn, then decided on an Auto-Lite. They are basically the same thing, operate similarly, and both are correct for that era and make.
This is the result...
Here's what it looked like when it arrived. Purchased untested, for $30.
I wasn't too concerned about how it looked on the outside, if it worked, it was getting refurbished. It didn't have continuity when I first tested it, but when I opened it, there was continuity in the wiring. It was simply out of mechanical adjustment.
It was stripped and sanded in preparation for painting. Interestingly enough, Auto-Lite re-stamped/reused the front bezel at some point in its past. Why? No clue, just interesting. HD-4017B is the model number for a 12V horn, which is what the back of the horn says it is. That's the important part anyway, since it's where the wiring is.
I used some cold bluing on the diaphragm and other hardware. I didn't want to paint the screws only for it to come off during reassembly.
Here's a before and after on the diaphragm.
New gaskets, traced from the old gaskets. These go on either side of the diaphragm to insulate it and seal off the inner workings. The gap at the bottom goes under the drain hole on the front bezel.
Assembled and ready for adjustment.
When you send current into this type of horn, the wire coil in the middle becomes an electromagnet, pulling the steel diaphragm back. On the back of the diaphragm is a small nub which is supposed to contact a mechanically adjustable circuit breaker. There is an adjustable brass striker screw in the center which needs to be made to just contact the middle of the diaphragm when it is at its most rearward point. When adjusted properly the breaker momentarily cancels power to the coil, freeing the diaphragm, and as that happens, the diaphragm has also made contact with the striker screw, which puts the voice into the horn. The process repeats as long as you hold power to the horn.
To start the adjustment process, back out the center striker screw so it's unable to touch the diaphragm. Now you need to get the horn to pull and release the diaphragm. The adjustment for the circuit breaker is the off-center, silver screw and lock nut. Too much adjustment one way, the diaphragm's nub doesn't hit the contact, too much the other way the nub makes contact, but the breaker can't travel back far enough to make the circuit "short". Either way you just get a "clunk". You need to set that screw in the middle, between clunks. It's kind of buzzing at this point but not fully voiced. You may be able to make out the pencil marks where I found those points to be. Once that is done, you lock it down with its lock nut.
To give the horn its full voice, you then adjust the center screw to strike the center of the diaphragm. This is where it gets loud. Again, there's a sweet spot for it and once you get there, you lock the striker screw with its lock nut.
I got a pigtail to be able to use the vehicle's existing horn connection. I added a mini-fuse holder on the positive line, and topped it with an insulator boot. Connections were soldered and covered with liquid tape, and the fuse splice was shrink wrapped as well.
I bought a spare horn to use its bracket. It was stripped, had its rust removed, and then repainted. The silver piece is a reproduction horn mount, the one that came on the horn was bent and just not worth the effort to make to work. All ready for installation.
Here it is installed this evening. All wired up, ready to roll.
So, after all that...
My current Jeep now sounds like my old Jeep.
When I got my 2005 LJ, I didn't plan on making many modifications. For some reason, in the last month I just had this urge to make my current Jeep a little like that old Willy's. Aside from its Go Devil engine, then most "Jeep" thing about that old Jeep was its horn. So I got searching, initially for a Sparton horn, then decided on an Auto-Lite. They are basically the same thing, operate similarly, and both are correct for that era and make.
This is the result...
Here's what it looked like when it arrived. Purchased untested, for $30.
I wasn't too concerned about how it looked on the outside, if it worked, it was getting refurbished. It didn't have continuity when I first tested it, but when I opened it, there was continuity in the wiring. It was simply out of mechanical adjustment.
It was stripped and sanded in preparation for painting. Interestingly enough, Auto-Lite re-stamped/reused the front bezel at some point in its past. Why? No clue, just interesting. HD-4017B is the model number for a 12V horn, which is what the back of the horn says it is. That's the important part anyway, since it's where the wiring is.
I used some cold bluing on the diaphragm and other hardware. I didn't want to paint the screws only for it to come off during reassembly.
Here's a before and after on the diaphragm.
New gaskets, traced from the old gaskets. These go on either side of the diaphragm to insulate it and seal off the inner workings. The gap at the bottom goes under the drain hole on the front bezel.
Assembled and ready for adjustment.
When you send current into this type of horn, the wire coil in the middle becomes an electromagnet, pulling the steel diaphragm back. On the back of the diaphragm is a small nub which is supposed to contact a mechanically adjustable circuit breaker. There is an adjustable brass striker screw in the center which needs to be made to just contact the middle of the diaphragm when it is at its most rearward point. When adjusted properly the breaker momentarily cancels power to the coil, freeing the diaphragm, and as that happens, the diaphragm has also made contact with the striker screw, which puts the voice into the horn. The process repeats as long as you hold power to the horn.
To start the adjustment process, back out the center striker screw so it's unable to touch the diaphragm. Now you need to get the horn to pull and release the diaphragm. The adjustment for the circuit breaker is the off-center, silver screw and lock nut. Too much adjustment one way, the diaphragm's nub doesn't hit the contact, too much the other way the nub makes contact, but the breaker can't travel back far enough to make the circuit "short". Either way you just get a "clunk". You need to set that screw in the middle, between clunks. It's kind of buzzing at this point but not fully voiced. You may be able to make out the pencil marks where I found those points to be. Once that is done, you lock it down with its lock nut.
To give the horn its full voice, you then adjust the center screw to strike the center of the diaphragm. This is where it gets loud. Again, there's a sweet spot for it and once you get there, you lock the striker screw with its lock nut.
I got a pigtail to be able to use the vehicle's existing horn connection. I added a mini-fuse holder on the positive line, and topped it with an insulator boot. Connections were soldered and covered with liquid tape, and the fuse splice was shrink wrapped as well.
I bought a spare horn to use its bracket. It was stripped, had its rust removed, and then repainted. The silver piece is a reproduction horn mount, the one that came on the horn was bent and just not worth the effort to make to work. All ready for installation.
Here it is installed this evening. All wired up, ready to roll.
So, after all that...
My current Jeep now sounds like my old Jeep.
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