I have a Wolo horn. Supposed to be simple one wire hookup, but I always thought it should be run on a relay, because if I hold it too long it would blow the horn fuse. Because I'm an idiot, my solution was instead to put a bigger fuse in. Not a lot bigger mind you, only like, 5 amps, but bigger. That pretty much ended the fuse blowing problem, and to be fair I rarely use the horn anyway.

The other day I'm driving down the highway with the headlights on, took an exit and found myself sitting behind some fool sitting at a green light. He's looking up and down the road, sitting there. I can see up the road, there's nothing there. Now a semi is coming down the ramp behind me, and I'm out of patience. Gave him the horn. It worked, for about two seconds... then it stopped and the wipers turned on.
Just the standard slow wipe. Can't turn them off, no fast wipe, delay, etc. Also, the left turn indicator is lit solid in the dash. I turn off the headlights and the turn indicator goes out and and wipers turn off. When the headlights are off, the wipers work normal. Turn on the headlights, the wipers go on and left turn lights up solid. Push the horn (which still doesn't work) and the left turn indicator lights up solid, and the wipers come on. Put on the left turn signal (which does still work) and the wipers run until I turn it off. Put on the hazards, same thing. Driving down the highway with the cruise control on and turn on the headlights, the cruise shuts off. Turn the lights off, cruise resumes. Using the left turn signal also cancels the cruise control until I shut it off, then cruise resumes. I should also mention that when the wipers come on because of headlights or turn signals, I believe it's only the three-wipe action you get when using the washer fluid, because when you turn off the lights or stop using the left turn signal, it continues slow wipe for exactly three wipes before shutting off. It does not, however, spray the fluid, so IDKWTF.
Fuses are all good. I had a spare multi-function switch that I know is good, but swapping it out changed nothing. I really don't have any idea where or how the left turn, headlights, cruise control, wipers and horn all interact, or how honking my horn could have enmeshed them all. PCM? Dunno. Hope not. Just wondering if anyone has encountered anything like this.

 

Sounds like you have melted wires causing short circuits. At $100.00 per hour labor at the dealer, you may be money ahead to just junk it.

 

I would never send this truck to a dealer, or any other vehicle for that matter. It won't be my money fixing it, my company has full time mechanics to keep the fleet running; and while I own this truck, 90% of the mileage is job related so it's more than qualified for fleet repairs. I personally have around $30K in it, I would not be "money ahead to junk it" even if I have to strip it to the bones and rebuild every god damned harness.

 

Well excuse me, you failed to disclose this information in your previous post. How would anyone know that you had all this free service from your employer which is a benefit many of us do not have, lucky you. Personally, I would not be so eager to broadcast my stupidity.

 

My situation has been brought up here multiple times over the years, and most of the people who have answered the few questions I've asked are well aware of it. EVEN IF IT HADN'T, that information is completely irrelevant. People who come here asking for experience aren't doing so because they plan to pay someone to fix it. If I take it somewhere, it will be because I trust them to know how, and I would have had no reason to ask anyone here for their experience in the first place. And if nobody here has had this same thing happen and can tell me something specific to look at, that's what I'll do and I don't care who pays for it.

For someone who isn't eager to broadcast stupidity: junking an otherwise perfectly good truck over a wiring problem is just dumb ******* stupid, whether you're paying someone else to fix it or not. Had I wanted to know if it was worth fixing, that's what I would have asked and I would have included any relevant financial information to aid the case. But I didn't. On the contrary, I asked if anyone had had an experience like this. I don't care if anyone thinks it's worth fixing or not. If you don't have an answer to the question asked: unsolicited advice which answers a question that wasn't even asked isn't better than just saying nothing.

 

As well known and popular as you say you are on this website, It's shocking to see that absolutely no member has stepped up to help you. Possibly because they all know you so well.

 

Possibly because all they all are long gone. I wouldn't have mentioned it, except that your join date is around the same age as mine, so there was a good chance you were around for all of it. On the other hand, your post count doesn't look like you were here much at all, so no surprise. I never said I was popular. I spent exponentially more time answering questions here than asking them, and much more in pm's than in the forum. It is what it is, and that's all but dead compared to a few years ago.