Not just another "Horn Doesn't Work!" request

I've got an '88 with a tilt wheel, no airbag. My horn has worked intermittently for nearly a year now. It seems to work when it wants to and not when I need it to. I nearly got sideswiped by an inattentive driver on a cell phone making a lane change because I couldn't "announce" my presence with my horn so I'm motivated to finally fix it.

The horn circuit is very simple. A spring loaded plunger sits under the steering wheel in contact with a spring steel plate. When you press the horn button, you press the plate until it contacts the steering column completing the ground to energize the horn relay. Everything in the horn circuit checks out OK. I can even run a jumper from the plunger to any ground (well almost, read on) and get the horn to blast. Any ground except the steering column itself.

My DVOM has an "audible" setting that plays a tone when continuity is detected. When I connect it to a known good ground and to my steering column at the steering wheel end, I get either no tone or a "scratchy" one. Measuring the resistance I got nearly 1k ohms. If I tilt the wheel to different positions or turn the wheel, the resistance fluctuates pretty wildly. If I press real hard on wheel itself, as if trying to bind the column, I can finally get tone and read a very low resistance.

Soooooo..... It seems that my column is not grounding properly. All other controls in the column work fine.

So, is there some kind of connection inside the column to ground the shaft? I can't believe the shaft only grounds by its connection along it length to the steering box and then to the chassis. The FSM and parts guide don't reveal any real details. I'd don't want to just start ripping my column apart unless there's no other way. I'd prefer to find the cause and fix it rather than jury-rig some other kind of horn button.

TIA

Have you replaced the relay I think it will put you back like $10.

If it does not work just take it back.

Good Luck

Been there, done that. When the horn "fails" I don't even get a click from the relay.

Anyone else?

I have the same problem, but like you I haven't found the solution.

I'm just kind of shooting in the dark here, but I can only think of a few spots that could interrupt the ground. I'm fairly certain it grounds through the steering wheel case, to the underdash metal brace and then the chassis. A likely spot to complete the ground is through the bearing, which is covered in grease.
I've had the column apart on various XJ`s tilt and non tilt and really can't remember seeing any special ground connections.
Maybe ohm check between the center shaft (suicide nut) and the underdash metal brace. From the brace to the chassis. It's possible the steering column case isn't making good contact with the under dash cross brace, then to chassis ground.
If the ground is interrupted deeper in the column it will likely be a pain. Grease in the wrong spot etc.
I have had trouble in the past with the slip ring, the brush, the spring and the die electric grease they use on the slip ring. I took all the old grease off, cleaned it all up well and my horn got fairly reliable.
The horn button is the ground for the relay, the coil in the relay has a fairly high resisitance, so the current to ground is just a trickle. Most any dirt or poor contact is gonna cuase trouble.

Thanks 8Mud.... I noticed in the parts guide that there's a ground clip that goes over one of the column mounting ears (inboard side). Since I'll have to pull the lower dash out and a few other things, I'll check it it later.

I know some vehicles have a copper ground strap in the flex joint between the lower steering shaft and steering box. Might check that the bolts & nuts are tight. Also with your DVOM connected as described, run a jumper wire between the lwr shaft and strg box just to see if the ground improves.

has anybody figured this out yet? my new colum is doing the same thing

I had the same problem and got tired of going behind the bumper. So i removed the horns and pulled the wire from in front of the batt. RE-routed it close to the fire wall. This allowed me to check them from a standing position. Cleaned the connections and tested both. I found that one horn did not work. I used a low and a high from a parts car and they sounded louder in that position. So I figuered, Why not try the other side too. I only had one high horn so I used it on the other side. People always think I have after market horns. P.S. they used to get intermitant power. Worked when testing and not when needed.