What I thought was going to be a simple repair is turning out to be a bit of a mystery. The first thing that I did was listen for the click of a relay, and not hearing that I assumed it to simply be a bad relay. Still, I pulled the compressor and oiled it, and checked for power with a meter- nothing. Everything pointed to the relay, so I swapped with the relay next to it (both are the same rating), and still nothing. So, what is your best guess? Am I not getting a connection when depressing the horn button? What is the easiest way to pull this to test it?
An easy first test is to remove the horn button and touch/jump the wire to a good ground and see if that actuates the system (I assume from your earlier post you have already applied +12V directly to the horn compressor and have confirmed it runs -- although measuring "no power present" is almost the same). If you need to go deeper: Remove the ...113 horn relay and measure the voltage between the 85 female terminal and the 86 female terminal when you press the horn button. If not +12V (or -12V depending on where you've got the "+" meter probe), measure the voltage from the 85 female socket to ground and from the 86 female socket to ground: If one of those terminals is +12V -- most likely you've got something wrong with the horn button grounding or its nearby wires or the steering column stuff and the next step would be to look there. As an additional test, if the horn button was working, when you measure the resistance from the other terminal to ground, when you push the horn button, it should go down to a few ohms. If neither is +12V relative to ground -- you have an upstream +12V power problem. Good hunting!
Terminal 85 to ground is just over 12V. There is no change when testing 85 - 86 when the horn is depressed. There is also no change on 86 to ground with the horn button depressed. So, horn button not working, or wiring between horn and fuseblock? Is there a reasonably easy way to get the horn button out, or do you have to tear the steering wheel out? Oh- I had tried the lighter, as it is on the same fuse. It worked fine.
The horn button just pops right out. If you need to use some dental floss to get under the edge but I can usually just grab the edge and pull.
Okay, we have to be getting close. I pulled the horn button, and there is a definite connection to the end of the (loose) wire when the button is depressed. Should there not be a wire to connect to the button, or does the short black wire on the button connect (should be soldered?) to the metal on the inside of the steering column? There is no wire to connect to, and i would assume that there should be. The only wire present is the one directly connected to the horn button.
Having the +12V present on terminal 85 is a good sign for the fuseblock/fuse and other upstream +12V items. I think that there's only one wire at the horn button switch IIRC. The other "wire" of the switch is/are the metal clips holding the horn button into the steering wheel -- and to have things work, these metal clips on the horn button have to (eventually) be connected to ground. If the wire connected to the horn button terminal seems cut/broken/unconnected, that's a problem. (I can't recall if there's a slip ring assembly inside the steering column, or if they just allow the wire to twist when turning, but) this wire should be a direct electrical connection from terminal 86 to the horn button terminal (and hence, when you ground this wire, you are grounding terminal 86, which closes the horn relay, and activates the air compressor, blowing the horn trumpets). Anyone have a jpeg of the steering column internals?
Should the wire from the horn button not connect to something? It literally just sits loose in the head of the steering wheel. Given that, what should I try connecting a ground to? I would think that depressing the horn button is intended to close a circuit, but I cannot see how there is any effect given the setup that I see.
It is this wire that you would ground, if the end not at the horn button was connected to something -- since it is not, you have a problem inside the steering column. This jpeg from Rob Garven indicates that your loose wire end should be riveted to the turn signal assembly (i.e., your fix lies under the steering wheel hub -- probably a break near that riveted connection): Image Unavailable, Please Login
WE HAVE A HORN! Well, a sad sounding noise, anyway. Now, it looks like I have to pull the steering wheel off to get at the 'rivet' where the wire broke off. I assume that I just need to pull the bolts holding the steering wheel in place (the eight or so allen-wrench end bolts)? Then I can just solder the wire back into place. And, thanks for all of the help!!
The bolts in the steering wheel seem to be extremely tight. Are they meant to come out, or should I be attacking this a different way? Has anyone else had this happen?
yes, the screws are very tight. there are a few threads about the repair you're doing and everyone mentions the tightness of the screws. a hammer impact tool seems to do the trick. one good thing is if you strip out the screwhead it's in an easy place to drill out. good luck
Impact wrench? *L* Wow, those things must really be in there! So, if they need to be drilled out, how bad is it to re-thread? And, where can one find replacement screws? I want to be prepared, just in case.
What you really want is a manual impact wrench. It's really simple, hit the end with a hammer and it causes the tip to rotate. In an Allen head screw, almost impossible to slip since the hammer hit keeps the bit in place in addition to providing a mechanical shock to loosen the item. The picture is Snap On (read $$$), but it should be available in a tool store for a reasonable price. I've only used mine a half dozen times in 20 years, but it always does the job. Particularly effective in loosening Philips screws. Of course you will need a 3/8" Allen head bit of the proper size. Image Unavailable, Please Login
It amazes me how Steve almost always has a picture of said problems that posters ask about.Good on you mate and keep up the good help!!!
That is a great idea- now I just need to track one down (or see if one of my mechanic friends has one).
Thanks for the kind words maurice. I do think a picture is worth a thousand words so it minimizes the amount of work and conveys things much more clearly (but I didn't just "have it" -- I had to make it from the unlabeled pic that Rob posted )
You don't need to remove the steering wheel from the hub to get to the column switch. Just poke the horn wire down into the recess it comes up thru, then remove the ring nut. You'll need to make a ring nut tool out of a piece of steel pipe from Home Depot, or by grinding down an impact socket. Or spring for one from Baum Tools for around $100 + shipping. Usually the steering wheel hub will pop right off of the shaft with a good yank. If not, then give the end of the nut a tap with a hammer & a brass drift. This will jar the hub loose. There's enough play in the system so the jar won't hurt anything. If tapping doesn't work, then remove a couple of those pesky screws that are opposite each other & use a steering wheel puller with a couple of long 5mm cap screws & washers to adapt the puller to them. BTW, The steering wheel screws are tight because F* put them on with Loctite. The impact wrench should break them off. The screws are just 5mm hex drive flat head screws. S/B available from McMaster-Carr, & certainly all the usual F* parts places like Ricambi carry them.
I managed to remove the nut fairly easily (I fashioned a tool from things that I have here), but the hub definitely is not going to move without some greater help. Maybe my big fingers just can't get a decent grip as there is very little to grab hold of. I will pick up a puller, and finish up this job. As with most of these things, the greatest portion of the time is locating the problem, not fixing it.
Completed and we now have a working horn. Of course, with my soldering skills that part took twice as long as normal, but still not all that long. Thanks to everyone for their help!!
