1946 Ignition switch repair

[PaulCDF]

Anyone have any suggestions, advice, instructions for rebuilding a Ignition switch on a 46?
I believe I have developed an internal short::
When I depress the horn it has started acting like a kill switch.
Well what can one expect after 80 years loyal service?

[pisten-bully]

Paul, I'd start by checking everything related to wires to and from the switch and horn. The way the switch and horn are wired lends itself to several sharp and cramped bends...especially where the wires connect to the switch terminals and then drop down below the mounting plate, and then the horn wire through the bars, and the horn itself needing to be insulated from the chassis.


sort of a rat's nest:

IMG_0132.jpg

[pisten-bully]

...then if you really eliminate a chafed wire, etc. and you want to open the switch:

remove the wires from the switch, then take the switch off the mounting plate:
P1010001.jpg

remove the brass bar and screws:
P1010002.jpg

split the switch case in half:
P1010003.jpg

remove the round insulating sheet so you can see the terminals inside the switch:
P1010006.jpg

this is inside the switch, the key rotates the piece and the spring loaded contacts move around and make contact with four terminals at a time:
P1010002.jpg

[tfburke3]

There is no ground in the switch to cause short,unless you have mag switch.I would check battery voltage when blowing horn.
I doubt the problem is in the switch.
Any positive wire touching ground would be apparent without touching horn button.
The horn negative ground to button would result in horn always on if shorted to ground.
Tom

[Skirted]

My guess is you have low voltage/battery/charging system issue. A horns operation is dang near a dead short and draws a lot of power. Seen this happen. Hit horn button and bike dies because no juice left for the ignition.

[FLFD7]

If you are going to open the switch back I suggest you do it inside a plastic bag. Often when you pull that center part out it sends the springs and brass barrels flying. Don't ask me how I know.
Joe