Silence is Golden - why won't my horn blow?

[Highwaylass]

2CV problem not a Lomax one. The horn has been silent for months. I've borrowed a spare, which works if I put it on the Lomax. It doesn't work on the 2CV. After I took the switch off the steering column to check for loose wires and put it back on, the horn still doesn't blow and now I have no lights either.

There's no obvious loose connections or chafed wires.

Has anyone else had this problem (and solved it)?

[Ken Hanna]

Unfortunately, if the switch is failing or has been disassembled and put back together incorrectly, things won't work as they should.
The photograph below shows the function of the wires connected to the switch and it should be possible to test the wiring using a short length of wire between the 'power in' screw and the various outlets.
A pair of scissors or circlip pliers would also work as the 'flying lead'...

2CV light switch connections by slcchassis, on Flickr

2CV light switch connections
This is on a 1986 car, colours of wires and end sleeves may vary for other years.
Yellow wire/ black sleeve; 'power in' from battery.
Grey wire/ blue sleeve; horn connection.
Green wire/ lilac sleeve; side & tail lights, dash light.
Grey wire/ yellow sleeve; main beam.
Green wire/ green sleeve + grey wire/ green sleeve; dipped beam plus feed to rear fog light through a separate switch.

Note that the star lock washers should be fitted 'French style', with the washer underneath the terminal, which prevents it being dragged round as the securing screw is tightened.
Some amateurs (& others) often get this wrong...

2CV problem not a Lomax one. The horn has been silent for months. I've borrowed a spare, which works if I put it on the Lomax. It doesn't work on the 2CV. After I took the switch off the steering column to check for loose wires and put it back on, the horn still doesn't blow and now I have no lights either.
There's no obvious loose connections or chafed wires.
Has anyone else had this problem (and solved it)?

[Highwaylass]

Thanks! I put it back together with care and copying my "spare" one from the parts stash.

What would the signs of a failing switch be? (apart from things not working, of course)

[Ken Hanna]

There was a daft 'dim-dip' setup used by Citroen in the later 2CVs that put all of the current for the headlights & sidelights through a contact in the switch which was originally designed to carry only the sidelight load.
If that setup wasn't disabled, the switch would overheat and the sprung contacts would no longer make reliable contact.
Driving down a dark country lane at night, the headlights would go out every time the car hit a bump, which wasn't too much fun...

Thanks! I put it back together with care and copying my "spare" one from the parts stash.
What would the signs of a failing switch be? (apart from things not working, of course)

[Jimmy Cooper]

Ah Ken, the French sense of humour? Wouldn't have me laughing either!!!!

[Highwaylass]

The horn didn't work because the wire had corroded about an inch short of the connection to the horn.

The lights didn't work because I wired the switch back up wrong.

d'oh!