My horn switch is not functioning, and I bought a new MotaLita wheel, with a center horn button....
Is there a way to run the horn + wire (PB), up the center of the column , to the new horn button? I can't seem to find a clever way to do this.
Thanks for suggestions (other than using the stalk, which doesn't work)...
Edward

 

Hi Edward,
If the remainder of your horn wiring is standard, there should be a Positive wire from the ignition switch to the Horn Relay via a fuse, and a wire from the Negative side of the Horn Relay to Ground via a Normally Open switch that is the Horn Button. Its not a good idea to have a Positive wire on a Negative Ground system running up through the steering column. The worst that can happen if the Negative wire shorts is the horn will sound. If the Positive wire shorts to Ground, things may get a bit hot before the hefty fuse that's used blows, and other devices depend on that same fuse. I'm sure you will find that this PB coloured wire will not be a Positive wire. You can check using a multi-metre to test for continuance between the wire of focus and Ground.

If your difficulty is actually threading the wire up through the steering column, a fairly reliable way is to use a suitable length of MIG welding wire. Turn a short length at one end back on itself, 6 to 12mm is plenty, so that you're not trying to feed a sharp ended piece of wire that is prone to catching on obstacles. You should be able to get this wire to feed through the length of the steering column without much hassle. Once the end emerges, overlap around 75mm of the Horn Switch wire with the MIG wire, twist the two together and use Tape to secure the two (electrical insulation tape is as good as any to use). Make sure you keep the bound tape joint as small as possible in diameter and without any edges that can catch on anything during it's journey up through the steering column. Proceed to pull the MIG wire and the attached Horn Switch wire through the steering column.


Regards,

Bill

 

Bill
Yes, the rest of the system is functioning...the PO used a doorbell button....I was hoping that I could make use of the center push button instead of the stalk....
How does the older "E" model make use of a push rod, and is there anyway to do that on the later car?
Thanks
Edward

 

Hi Edward,
The Purple and Black wire will go to Earth via the Turn Signal Stalk. Irrespective of its form, Centre Push Button, or Turn Signal Stalk, its just a Normally Open Switch. The Turn Signal Stalk system will have the Turn Signal Stalk as the switch installed so as to create continuance to Ground when the switch is closed. If you want this system, all you need to do is get the appropriate hardware (Turn Signal with inbuilt switch) attach the PB wire from the negative side of the Horn Relay to one side of the Turn Signal switch, then take another wire from the other side of the switch straight to Ground. When this switch is closed by actuating the Stalk, continuance will be made to ground and in turn, the Horn Relay will switch.

If you want to use the Centre Push Button, do the same as explained above for the Turn Signal switch, but for the Centre Push Button.



Regards,

Bill

 

This repair was a challenge, but I was able to get the stalk functioning again....
First, the PB wire was disconnected at the back of the stalk, leaving a few inches of wire...
Then the stalk was removed from the turn signal, using some brute force....The end of the stalk is splined, and fits tightly into the mounting plate.
Unscrewing the button on the now-removed stalk, revealed a copper cone on the end of the button, along with a good-sided spring.
Then the outer plastic cover is easily slid off the stalk....You will now see the metal tube, topped by the two switch contacts mounted in nylon....
The black rubber sleeve can be carefully removed, and now you can see the whole tube...
At the top of the metal tube, you can see two machine "detents" , where the inner parts are held in place...
Before going further, test the contacts , with an ohm meter, to see if there really is a short-to-ground...Only one of the brass fingers is ground, the other only goes to the PB wire....If you show "0" ohms on both sides, you will have to take it apart, to fix it.
Chances are, the wire overheated and the insulation was burned off, or the connection got twisted.
Taking it appart requires very delicate drilling to open the detent holes, but not drill into the brass ground, or the nylon sleeve , inside....
Once drilled out, there is still a rubber grommet inside the metal tube, that will only allow the nylon part to be pulled out part way, and be careful not to destroy the brass contacts....Once the soldered area of the old wire is exposed, best to cut the wire, and pull it through the other end....Then withdraw the nylon part, along with the two brass "fingers"....
From here, it's a simple matter of de-soldering the old wire, and putting the new wire on the end, along with heat shrink....The ground sleeve is split, and will have to be forced off, and then back on , after the heat shrink. Of course , you will also have to drill out the rubber insulation in the tube , to allow the wire to go back into it.
One more thing...Line up the original detent holes, that you drilled and carefully use a punch to re-detent the holes.....That will help keep things in place, again.
This fix works, and will save buying a new turn-signal switch....If it fails, you have only lost the time.....
Edward