Horn Help

[tvacc]

Hi all,

I had Brian Buckland here for a few days, and we messed around with my Elan. He helped me balance my carbs and work on some other issues. It is amazing how much he knows. He right away saw so many things wrong with the car. It was scary. Here I think I know alot about Elans and in 10 minutes made me feel, well....sort of like I did not know that much. Not in a bad way, in that he did anything to do so. It was just obvious in comparison to what I know, he is so far above me. We did a lot of laughing and telling stories. It was one heck of a great day. Of course, when he heard that Bob Dance was coming the next day, he made me promise not to ask him how to tune Webers in front of Bob, but I did anyways.....gotcha Brian. If you ever get a chance to meet Brian, and to buy his book, do so. Hell of a nice guy.

One of the things I asked him about but we never really got into was my horns. We suspected it was grounds, but with people coming over and dinner and all of that we never really looked at it. The next day he gave his talk to the LOONYs and others from around the eastern USA and Canada, and before we knew it, his plane was leaving in an hour and we had to get to the airport. Brian could have talked for another few hours on Elans. But it will be one of the weekends I will not soon forget.

anyways.....

Maybe I am getting old but I just cannot seem to remember how the horns work. I have checked the purble, purple/black wires down at left hand horn and the white, white black wires on the right side horn. None of these are getting 12 volts I press the horn button. I checked the horn button and it does get continuity between the side wire and the center connector that hits the spring loaded button in the wheel center.

I assume the purple and purple/black wires are both hot or is one ground? I have a blown up wiring diagram and it appears to me that the purple/black does go back to the main 12 volt bus. The horns work if I ground them and put power to the top connectors. I can also put in a set of relays if necessary.

Is the horn switch in the center of the wheel just a "ground" completion? I assume that there is not a 12 volts positive in there, correct?

Is the purple black supposed to be hot 12 volts?

Well any help you can give will be appreciated.

And I just noticed that the fuel gauge does not work. Any connection do you think? I checked the wires on the fuel sender and the ground was actually off, but putting it back on did not fix the gauge.

Thanks guys.
Any help appreciated.

[UAB807F]

Hi Tony,

I think (notice the word "think" ) that the horn is meant to work with a +12v feed to the horn and then the return from the horn goes to earth via the horn push & steering column itself. The 12v feed to the horn is fuse protected and any short in the wiring from the horn to the steering column would just sound the horn rather than cause a fire. So one side of the horn should show a +12v on your meter and as you've proved the horns work and are getting a 12v feed, I'd check the earth return on the steering column. On mine it's a connection made on the alloy housing of steering rack itself.

I can't see any connection with the fuel gauge problem. These work on a similar principle of +ve feed to the gauge and then to earth via the resistance of the tank sender. First is to confirm that you're getting a +ve feed to one side of the gauge (I think it's green, but check because it's a while since I fixed mine). If so, then a temporary earth wire to the other side of the gauge will show a deflection and prove if the gauge itself is ok. Assuming that's ok, check for continuity along the gauge & tank sender wiring and from the tank sender to earth. If both those circuits are working then it looks like an internal tank sender problem.

I don't know the resistances of the senders used on the Elan off hand, but have just repaired the one on my Europa which is between 10/20 to 220/230 ohms resistance across the range. (which incidentally was the same as an MGB unit) So regardless of how much fuel is in the tank you should get some sort of reading. if you get no reading across the sender terminals then it's likely to have a break in the internal tank sender resistor wire.

Brian

[oldelanman]

Hi Tony,
As you have no power to the horn itself I would suspect the fuse - check the fuse itself but also clean up the clips which hold it and the spade terminals on the fuse box - they often get tarnished and cause a bad connection. When checking earth connections don't forget there is a bridge wire across the steering column U/J which often gets overlooked.

The fuel gauge is fed from the voltage stabiliser which is mounted on the back of the speedo - if the gauge is getting no power it's worth checking that out first.

[neilsjuke]

Check fuse box and clean
Neil

[tvacc]

First time I have had a chance to log back in. Busy all weekend getting ready for winter here in Buffalo.
I actually have not touched the car since Friday. Too busy mowing the lawn, putting away things that will freeze,
Where does the ground strap run from and to? I remember seeing one on my other Elans.

So am I to understand that the horns are always grounded by some sort of grounding strap to the rack?

That there should always be 12 volts to the green wire on one of the horn terminals?

The the green/black wire is a completion of a ground (from the horn button) that signals when the horn should sound by completing the "ground" circuit when you push the button?

Why would the horns then always be gounded by the strap if by grounding them with the horn button sets them off?

Sorry. Brian had mentioned something about the grounding strap and the rack when he looked at my car. We just did not get more into it because of the time element.

[types26/36]

Because the rack is mounted on rubber it has to be grounded (to ground the steering shaft) it also needs a bridge over the steering coupling it has rubber in it as well.

[tvacc]

thanks for the photo. helped me get a handle on this. have not looked at it yet. At work, but plan to look at it tonight after I finish mowing the last 1/2 acre.

[oldelanman]

Hi Tony,
If you are talking about an Elan the original horn wiring is not green - maybe you car has been rewired.

Fuse box to horn(s) is purple
Horn(s) to horn push button is purple/black

[tvacc]

I am sorry, been a long day so far. I meant to say purple and purple/black.

[pereirac]

I wired a relay into my horn circuit (my Sprint has air horns), it certainly seems to help..

Carl

[JJDraper]

This may help.. I think it originally came from these hallowed archives!

Jeremy

[tvacc]

Hi all,

An update. I went to work on the car today. It appears there was a ground strap from the frame to the rack. It was sort of hidden that that is why Brian and I missed it. I also found that there is no unswitched power to the fuse box. So after I turned on the ignition, I was able to get horn by grounding the wire to the "ground" side of the horn. I then worked backward getting horn by grounding frist to the rack, then the steering column and then the purple wire under the dash. But when I grounded to the button in the center of the steerng whee, nothing.

It ended up being the connector under the dash. Just one of those Lucas Prince of Darkness things. Cleaned that up and all is fine. I have HORN!!!

Thanks all.

[Rozzer]

Rather than start another thread, I thought I would re-energise this one - particularly as it appeared to have such a positive outcome (sorry) last time....

The horn sometimes actuates when I turn the wheel! I dis-assembled the steering boss, and cleaned up the contacts, took the car out, and all was well until I turned into the garage at the end of the drive, and off went the horn again!

I suspect the spring-loaded contact that sits on the back of the steering boss, but has anyone else had this fun-and-games and found anything else that might be the culprit?

Thanks in advance....

Ashton

[RogerFrench]

Ashton, I suspect your steering wheel is a bit too close to the steering column shroud / top support assembly.
Try slacking off the clamp on the inner column, where the safety joint is, and pull the wheel and column up a bit.Check the horn still works, tighten the clamp and try again.

[Quart Meg Miles]

If your car is an early one without steering lock it is easier to unclamp the shroud holding the Herald switches and push that a little deeper. There are just two nuts holding the clamp in place and I've had to insert extra padding as it was sliding and closing the gap to the wheel boss every six months.