Horn goes off when it's too cold

[nmacarthur]

Greetings (it's been a little while) - I was researching the forum and had no luck seeing if anyone else had this similar problem. When the temp drops (has always been at night), my horn will go off. It's a 1980 Caddy and I've only seen two possibilities online:

1) the plastic in the steering wheel shrinking and warping in the cold allowing the horn switch to contact

2) A shorted wire or an alarm system malfunction

I don't have an alarm, so I'm curious to see if anyone else has had this happen or is familiar w/ this problem. Currently, I just take out the fuse that connects the horn and the power door locks when I know it will get cold.

[Faded Crest]

I've not heard of that problem, but if it's youur horn button, it may be too close to the contacts... Is the horn button overly sensitive? If so, remove the steering wheel center by removing the 2 screws behind the wheel and slightly bend it so it won't make contact so easily. It's been years since I have had a center off, but once you take it off, you will be able to see what makes contact. If I remember correctly, there is a spring-loaded plunger type electrical contact that sits in a plastic sleeve that you have to remove, so watch out not to damage that. You might have to turn it about 1/4 turn to take it loose?... I think.

That comes to mind because I once switched out a steering wheel center on an 80's Cad, and the replacement center pad activated the horn as soon as I installed it. I had to bend it to make it work right. But I guess to test the cause, you can leave the center pad off one night to see if the horn still blows. Good luck

[cadillac_al]

I had a 82 Olds Ninety Eight that used to do that; it was always 3 or 4 in the morning. I never bothered to trace the problem because I "assumed" it was a shorted wire in the column. I think it did have a fairly large horm pad so it could have been an adjustment problem. I just unplugged the horns in the winter time on mine. My dad had a 69 Chev pick up and the horn would blow with the left blinker. I'm pretty sure that was a short and that's probably why I assume every problem in a steering column is a shorted wire somewhere and not worth fixing. I would try messing with the horn pad and see what happens.

[codewize]

LOL had that in my 78 Coupe. Woke the whole damn neighborhood up at 5am.

The contacts on the wheel are very close together. When it gets extremely cold out, that happens. I just pulled the fuse in the winter time.

It's nice to have some old timers around here isn't it. I also found that banging on the wheel a few times will make it stop. I'm sure there's a fix but I never took the time.

[thegrapeone]

My '78 Phaeton does the same thing and it seems like 55 degrees is the switch it on temp. I think it is in the horn pad because the left side of the pad is super sensitive - you can just lightly touch the left side and it blows the horns, and sometimes just hitting the steering wheel really hard a few times will stop it. I just disconnect the battery when it's going to be cold here in north Florida and don't drive it and one of these days will get around to checking out the contacts.

[lochenjons]

reminds me of when i first bought my '69. hooked the battery up to a charger cause it was dead and as soon as i made contact the horn went off. scared the s*** outta me

[CaddymanTom]

My 78 Seville has the same problem. It is the cold and the cover on the horn shrinks and makes contact. I too remove the fuse in the winter time. It happens early early in the morning in the winter time here. Yes it does get cold here in Palm Springs CA in the winter.

[lochenjons]

well did you figure out the problem?

[nmacarthur]

I'm finally getting a moment to log back in again - I had removed my fuse when I knew it was getting cold - so I haven't looked at the horn pad yet (this weekend I will be able to). Yesterday was nice, but then this morning the horn went off again. It was cool but not cold (go figure) - so out the fuse went. I'll update once I fiddle with under the horn pad.

[nmacarthur]

Problem: Horn goes off when temperature drops.
Horn may go off easily when slightly pressed.

Solution: Foam may have compressed over the years. Remove the pad from the steering wheel and see where the foam may need extra padding.

Tools/supplies needed:
9/32 socket (your mileage may vary
Pop rivet gun
Rivets (sized to replace existing rivets)
1/2" foam padding
scissors
General purpose adhesive spray


Remove screws from the back of steering wheel:



Remove horn pad and turn over. Cut rivets from the back metal plate:



Steering wheel without horn pad:



Horn pad, copper plate with foam cushion, top mounting plate:



Inspect foam on copper plate to see where it may have compressed. These are the areas to replace with new foam padding:



1/2" Green padding foam. Found at shops that specialize in upholstery (Like JoAnn's Fabrics)



Cut a strip about 1/4" thickness:



Cut strips to fit over the areas that have been compressed:



On a covered area using general purpose spray adhesive, carefully spray the back of each strip and apply it to the areas needing new padding. Trim any foam that may be too long:




Once complete, place copper plate back on horn pad and test to see if connection will only be made when pressing horn pad down. Rivet mounting cover in place and reattach horn pad back to steering wheel.