Horn and Generator vs Alternator

[sdkunick]

I'm planning on swapping my generator out for an alternator on my 64 Sprint. I've got the brackets and pulleys figured out but I know there is a difference in the horn ring in the steering column. Something like 1 contact vs 2 contacts. What do I have to do to make the horn work correctly when I do the swap?

[Luva65wagon]

I know the alternator version Falcons removed the horn relay, but never studied why the Gen/Alt factored into the horn circuit changes. I've always had extra 65 wiring harnesses and just modified them onto the cars I've had, but I'll study the wiring diagrams to see what and why of this - if even just to have it documented.

[Luva65wagon]

With a quick look at the two style wiring diagrams, the gen versions, or those with a relay (whether the two were coincidental or not), the cars with a relay uses the horn button to "switch" the ground circuit. So push the button and the horn wire grounds at the steering wheel, activates the relay, horns honk. On the non-relay (65 cars and maybe newer... didn't look further) the horn button switches +12V, so you have a hot wire to the button from the fuse block to headlight switch to horn button... and the other wire goes directly to the horn. Push the horn and connect 12V between fuse block and horn, horns honk.

From my point of view, though the newer style would work (obviously has), running a relay is always better, since horns do actually draw a bit more current than you probably want to run in a regular switch. Whereas a relay switch would carry the same current for the same function, when the contacts start to fry you replace the relay and not the horn button contacts.

I also don't think it matters using a relay for the ALT version, just run a new fused wire from the solenoid to the relay, instead of from the GEN/REG and use the one-wire "switch ground" style on the horn button as it currently wired on 64-earlier cars.

Hope this made some sense. May look at it tonight and say, "I could'a said that better...."

[sdkunick]

You wouldn't happen to have a picture of those 2 wiring diagrams would you? Do you know of somewhere on line that they exist. Maybe TFFN?

[Luva65wagon]

I have one digital and one not. Here's the pre-65.

[Luva65wagon]

This is for a 65 Mustang, but the horn and wiring of it are the same as a 65 Falcon. Other things vary, but not by much.