Electrical Wizard that I am (not) I figured if I merely connected into the existing two wires and ran them over to the other side of the car, I'd have it nailed. Not. Either horn will work but not both. So, I ran just power over to the second horn, and grounded it to the frame. It honks as soon as the key is turned on. Where is my stupidity this time?

Take the bumper off, find the two wires that are turned back, un wrap and connect. Piece of cake! The factory already wired it.

Do I really have to take the bumper off? Where did they hide them?

The wires should be easy to access from behind the fog light grille without removing the bumper.

Depending on the horn you are adding, you may want to put a relay in line.

When I put supertones on the car, that is what I had to do.

Zach

Chris...the wires are there for fog lights on both sides (white and brown) even the car has no fog lights currently (does have the dash switch). The wring for a horn is only present on the left side.

A pair of Fiamms. What do I ask for at my local Radio Shack?

Not quite true. If he has a '70 (which i think he has) there's a good chance there is no factory wiring for a second horn ...

Andy

Andy is right again (damnit!).

Disconnect the ground from the first horn. Leave the power connected to it. Run a wire from the ground spade on the first horn to the power spade on the second horn. Run a wire from the ground spade of the second horn to the ground wire of the first horn.

Voila!
Andy

...That should work!....aaaoooogggaaa..honk,beep beep!!!!!
(horn is ground?)

Would that not result in only 6V being delivered to each horn? Series Cct.

I think the way he tried should be the best way. Parallel cct. T off both terminals on the original horn and tie into the corresponding terminals on the 2nd horn. Not sure why his first try didn't work. You will be doubling the current that the original wire and fuse is carrying so a relay may be required.

I installed a pair of super loud FIAMM's. Wouldn't work with stock wiring. Installed a relay, and it works great! I drew a schematic and placed it somewhere... I'll have to look for it. It was pretty straight forward, IIRC.

Andy...if this is what you were suggesting, it didn't work:
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This is a good representation of a relay setup for the horn!Click to view attachment

Good for you...meaningless to me.

Are you sure the PO didn't hack into your horn wiring?

Andy

Doesn't look like it was hacked into. The fog light wiring is there and the factory colored wires to the single horn. 70's only had a single horn, right? The horn works perfectly. I just want to add another horn on the other side in order to be heard. Seems like a relay may be the answer. Gotta find out what kind of relay I need, and how to wire it in, right?

This is how I would do it. Both horns get 12 Volts this way. If you pop a fuse it means you need the relay. Horn #2 is the original, Horn #1 the new one. Doesn't matter electrically - just that your original wires are already there.
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Exactly how I started out this morning but they wouldn't work that way. Do I need a relay? Where does it go in the scheme of things?

The relay is required when putting an increased load on an existing cct. It does not affect the actual cct. Think of it as adding a more powerful switch to the horns.

This should work. In your first post you said that either horn would work but not both at the same time. What were you doing to test each horn individually in that setup? Do you have a volt meter? Test Light?

I'd suggest you try this setup again. Which horn works?

Just checked with my good friend Haynes. This is pretty much how the factory option was wired. There is a minor difference but it won't make any difference to "work/doesn't work". They run the hot wire (blk/yellow) over to the second horn but use a ground over on the other side of the car rather than running the grounc (brown) back to the first horn's ground.

The wiring diagram also shows that the stock wiring is using a relay already. Reduces the current to the horn button.

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You need a relay. Your horns are drawing too much power.

Autozone, Radioshack, etc will all have basic 4 or 5 prong relays for ~$3.

Remember, ALWAYS + to +, ground to body. NEVER + to ground. That is just causing a short.

Come over tomorrow. As I said in my PM, I am going to be wiring a little on my 914, and you can see how I have y relay wired - since the diagram is usually the same. I can call Joe and we can grill some zucchini and meat of some sort, wire cars and drink beer. What could possibly be better?

Zach

I just meant that either horn would work as long as I disabled the oter one...have them both wired in series and there was just a sick squeek coming out of one or both (not sure). I'm gonna wire a relay in early next week. Let ya'll know. Thanks.

Wow...love to, but I'm leading the SOB (Semites On BIkes) out to Shepherdstown, WV for the day. Monday I'll be hitting Radio Shack and finishing this little project up. Thanks.

I used 16 ga. wire to go over to the second horn...could THAT be the problem? If te answer is "no", I'll wire a relay in early next week.

Sorry guys but this diagram is 72 and later only. I just had a look at the 70/71 diagram and the horn is quite different. If you ground an early car the horn will sound continuously. I'll post another diagram in the morning. For the early cars parallel should work but it will place an extra load on the horn switch which will likely be unhealthy for the wiring. Zach has it right - use a relay.

As usual, my spur of the moment, don't check with the wife social planning has failed.

Given that I didnot check with my wife and she may have other plans for me, maybe this was a good thing. :-)

16ga wire would not cause your issues. Using the heavier wire is good. Loud horns need a lot of current. The stock wires are not giving enough, causing your issues.

zach

Zack (or anybody else who's run a relay off of the battery)...what route did you use to get the wire from the hell hole up to the front grill? Anything easier than the tunnel?

I ran it through the firewall with the rest of the wires in the tunnel (did it after the fact, not that bad). But then I ran it above the tunnel and under the carpet for the rest of the way through the cab. All my wires are run this way, not in the tunnel, but in the channel on top of the tunnel.

Zach

Gonna assume that you're correctly identifying the firewall as the bulkhead between the engine and cab. So, you ran it into the tunnel but then exited the tunnel through the plate right at the ass end of the tunnel?

No. on mine, thre is an opening a few inches down the tunnel into a channel on top of the tunnel. Stock, some wires were in the tunnel, and some in the channel. When I rewired the car, I just put all of them in channel.

It might be a late car thing, and early cars may not have the channel.

Zach

Voila ! Blow your fuckin' ears out ! Special thanks to Zack who gave me guidance through PM's and furthered my education. Two pics I took today (sorry I left out a "C" Zack).
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