A ghost in the machine...honking my horn.

agfours · agfours's Garage

My horn likes to stick on at random times, most of the time when the car is just parked. Only happens once every couple of weeks, and there is no clear association I can make with weather, prior driving patterns, etc.

My suspicion is that either the relay is bad, as I can unplug the relay, then plug it back in later and the horn will not be blowing...

What causes a relay to just randomly trip? Cold temps maybe? (doesn't happen every time the weather gets cold...) Weakened contacts?

Just need some reassurance before dropping $30... or is there a way to test an intermittent relay?

Thanks!

porschenut · 04-09-2014, 07:17 AM

When the horn is blowing, pull the relay and then immediately plug it back in. If the horn resumes, the relay is not the problem. If the horn does not resume, the relay is the culprit.

Relays wear out and fail, as do all electrical components eventually.

GH85Carrera · GH85Carrera's Garage

Is this on the 87 911?

My horn started to honk by itself on my 914. The rubber spacer in the behind the horn button was old and flattened. Of course my horn started honking as I pulled up behind two bikers. They were not amused. I just replaced the rubber bits and it was cured.

agfours · agfours's Garage

Yes, this is on the '87. I hear ya on the high annoyance factor....i pulled up to a restaurant in a great front row spot where there was a girl talking on her cell phone who had obviously stepped outside because the restaurant was too loud to hear the conversation on the other end. You know the rest of the story.... luckily I've gotten the drill down to about 7 seconds to pull the release, jump out of the car, get the hood open, pull the carpet back, pull the relay...about 6 seconds longer than I'd like.

I'll check the pads again...

awhnry · awhnry's Garage

My '87 developed a nick in the ground wire and it took several rewirings to locate the bad place in the line. Yes, it does seem to blow at the worst possible times.

GH85Carrera · GH85Carrera's Garage

Quote:

Originally Posted by awhnry

My '87 developed a nick in the ground wire and it took several rewirings to locate the bad place in the line. Yes, it does seem to blow at the worst possible times.

That happened to my wife when she was driving my El Camino. It honked a perfect toot-toot just as she drove by a 70 year old neighbor man bending over to pick up his newspaper. My wife was not amused.