While reassembling my ‘72 project it’s come time to figure out my horn situation. I found these two horns in a box and am not sure if one or both were original to the ‘72. My car does have the wiring for two horns but I can not remember if both of these were on it before disassembly. I kind of think the smaller one was on my ‘74 parts car.

Either way, I need to know: are these two normally used in conjunction with one another as low/high (quiet/loud ) - if that can even be determined without part #s? If they are both of the same volume I guess I’d just be using one - or do two quiet ones make a loud Are there any knowledgeable horn experts that can help? Thanks

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I believe the one on the left is stock, at least it looks like the one I have on my -70. If you decide not to use it, let me know. Mine sound kind of sick...

From a 75 914

Ok, that would make since as this particular ‘72 tends to have attributes of the early cars (‘72 being a transitional year).

Can someone refresh my memory:
1) did they indeed come in hi/low varieties or were they all of the same sound level [w/ two horns just equaling a louder set up]?
2) If two are installed (and one is louder than the other), is there a way that they get individually activated when pressing the horn button/pad?

Originality doesn’t really matter to me tho on this build. I’d be willing to run both of these horns IF they work together. Any reason why they wouldn’t?

@Jett do you have access to the p/n’s on those that you posted, and know which is which.. so I can figure out what the small one is that I have? Thanks.

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The horn on the left is an early stock Hella horn as noted by the screws around the perimeter....they can be taken apart very easily to repair...Later Hella horns have rivets which you have to drill out and replace to repair....Stock was one horn and second horn was an option and later added into the "Appearance Group" trim package....the 914-6 came stock with two horns..
I think the two horns Hz was 400 and 335

Good info, very helpful - thanks!!

Good news: is that I found two more horns.. one large early w/ screws around the perimeter. And another that looks like the late one I already pictured but it’s larger (yet not quite as large as the early ones either).

Bad news: is that only one of the four horns work when hooked directly to a good battery. It’s the larger late one that I went back and found. Glad I kept searching! I’ll run it solo on my current project until I can get the others to work or replaced.

Btw, I see no indication on the early horns as to what Hz they may be (again those are both physically the same size). Interestingly tho, the late looking ones that I have are both 335Hz, despite being sized differently. The 335Hz was actually louder than I had expected, so it’ll work for now.

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The Hz noting is on the backside....sometime on the early horn it's hard to see because of all the crud/dirt covering it....
The early horns can usually be repaired....really it's just a clean up of the internals....it's an electro magnet pulling on a metal disc....
Open one up with the screws (good idea to soak) and check it out....you can't hurt it

Okay I'm putting the horns back after a respray of my 74 2.0. One is stock Hella, other is add on (that came with appearance group?). There are two sets of wires on each side, one brown (obviously ground), and the other a color (sorry, don't remember now). My question is, which gets plugged in to which side of the connectors on the horns? Or does it matter. There's nothing I can see on the horns themselves to indicate which side the wires should go. BTW, both horns work, but I have yet to deal with the horn wires in the steering column. Project for another day.

I've brought old horns back to life by submerging them in WD/40, letting sit a couple of days.
I'll then go nuts with the blow gun and the needle tip...

Try them again, lather rinse repeat.

Slap them around while applying power.

I saved many this way (not a single Porsche yet!).

All of the ones I have come across (mostly Japanese sportscars) were riveted and could not be dissembled easily.

I have saved some German ones (Bosch?) but they were BMW/Mercedes.

It's really just like johnhora posted, just clean them up!

As for polarity I'd first check if either of the posts have continuity to the horn case.
If one does, I'd put the ground on that one.
If one has continuity the other side will as well but it will show the resistance of the coil and its reading will be different than the other.
Lowest resistance to case gets ground.
Both not have continuity?
I'd try it both ways and use what sounds best.

I'll look to my stock 75 and see how Porsche did it and report back.

Here's the horn from my '74 (11/73 build date) for reference. I see the rivets mentioned earlier, and I do see the Hz listed on the back.
Click to view attachment Click to view attachment

Hope that helps...

I 've hooked up the horns to a battery and they work, but I want to make sure I'm connecting them correctly.