Horn wiring

[rdorman]

One of the things I struggle most with is wiring. I am wiring in some Hella horns and NEED HELP.

Looking at the wiring diagram for my car, it shows two wires. One is wire 21 black that runs from the fuse box to the front of the chassis. The other is black 18 that runs from the fuse box to the steering column. The horn relay is marked terminals 30, to 12 volt; terminal 87 to the horns; terminal 85 to another 12 volt and terminal 86 to the horn button (one from finishline for dash mount) and then to ground I am assuming. 85 and 86 active the relay while 30 and 87 supply the power to the horns.

Question is, how to wire. Considering the physical location of all of this, what is the best way to connect what? Will a relay work if you connect power in reverse? For instance, if you apply power to 86 and ground 85 will that work?

Thanks
Rick

[pgermond]

Hi Rick,

I see you posted over on CC and are getting advice, I would like to help but I'm confused by your question. The dash and steering harness are pre-assembled, as is the fuse panel (at least it was with mine - ProDesign). The horn wire numbers are the same and I can send you a scanned image from the manual of how it is all routed if need be. Are you replacing horns, or installing them for the first time?

BTW - If you reverse the leads on the horn relay the horns will suck - rather than blow [}] Sorry..... couldn't pass that one up.

Let me know if I can help.

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[rdorman]

Thanks Phil. I am wiring them up for the first time and I actually have the old wiring diagram that came with the car. Unfortuniatly, it is not really clear or at least it conflicts with the directions that came with the relay. This diagram, under 'fuse block' states "18 black to the (-) on the horn relay coil", this would be terminal 86 since the directions show 86 to the horn button (and then to ground) with 85 to 12 volt to energize the relay. Of course much has changed since back when my car was built.

I am thinking mount the relay at the fuse block, run 18 to the switch, from the switch to 85, from 86 to ground. This would complete the 'energizer' circuit. From there, cut into black 21 running it from the fuse box to terminal 30 and then connect 87 to the horns and then on to ground.

Thoughts?

Rick

[pgermond]

Rick,

My fuse panel came with the horn relay mounted on the fuse panel.... yours didn't?

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[rdorman]

Darn good question! I guess I will have to look! 20 year old car, who knows! That would certainly cut out the questions.
THanks
Rick

[ralphscott]

Rick my car is just 5 years old and like Phil's mine came with the horn relay in the fuse box, I replaced my Whol horns with Hella's last week. The only thing that I can tell you is that the horn rely in the fuse box (that is if you have one)is sufficent and I did not have to use the Hella relay. Alan mounts his horns off of the front body mount. I am still experimenting with where I want them as the the space between the tire and the body mount looks a little too tight for a forward facing horn, 'cause the Hella's are so wide. I mounted mine under the sway bar off of the back most bracket bolt and used a 90 degree angle, (powdercoated) I also drilled another hole in the mounting strap so I would have two points to attach it to the bracket. (Slow drilling!) Where I had to make a ground connection I used (once I ground away some powder coat) serrated washer under my flat washer and dilectric grease to make sure I had a good and lasting ground.

Good luck.

Ralph

[pgermond]

Rick, How did you make out with the horns? I can shoot you a photo of where I mounted mine if you are interested.

Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[rdorman]

I just rev it up a bit to let them know I am coming! Never had horns. Heck I once had a daily driver with no wipers so no horns is a piece of cake!

Picture would be great.

Thanks
Rick

[pgermond]

One on each side -



Phil

427 Roadster, #4279436
Southern Automotive FE
3:31 and Toploader

Roseville (N.Cal)

[rdorman]

Thanks for the pic!

See all of you in 37 days!

Rick

[rdorman]

Turned out to be a real snap. Thanks to the wiring diagram and the relay alreay in place. I was suprised that a 20+ year old relay that had never been used worked!
Thanks for the help
Rick